[Silabs] Use a common main files across All examples

[jepenven-silabs]

Move duplicated main.cpp file to common example code.
Also add Buttons to the platform abstraction manager.

[github-actions]

PR #26342: Size comparison from 328c553 to 2b6cca2

Increases (3 builds for bl702, cc32xx, qpg)

platform	target	config	section	328c553	2b6cca2	change	% change
bl702	lighting-app	bl702	.debug_info	40736904	40736905	1	0.0
			.text	964580	964582	2	0.0
cc32xx	lock	CC3235SF_LAUNCHXL	.debug_info	19511288	19511289	1	0.0
qpg	lighting-app	qpg6105+debug	(read/write)	1167608	1167616	8	0.0
			.text	614708	614716	8	0.0

Decreases (2 builds for bl702, nrfconnect)

platform	target	config	section	328c553	2b6cca2	change	% change
bl702	lighting-app	bl702+rpc	.debug_info	45431975	45431974	-1	-0.0
			.text	1036974	1036972	-2	-0.0
nrfconnect	all-clusters-app	nrf52840dk_nrf52840	text	808660	808656	-4	-0.0

Full report (13 builds for bl602, bl702, cc32xx, linux, mbed, nrfconnect, qpg)

platform	target	config	section	328c553	2b6cca2	change	% change
bl602	lighting-app	bl602	(read/write)	1354458	1354458	0	0.0
			.bss	87886	87886	0	0.0
			.data	9648	9648	0	0.0
			.text	1035446	1035446	0	0.0
		bl602+rpc	(read/write)	1400734	1400734	0	0.0
			.bss	95934	95934	0	0.0
			.data	10040	10040	0	0.0
			.text	1066804	1066804	0	0.0
bl702	lighting-app	bl702		0	0	0	0.0
			(read only)	3358	3358	0	0.0
			(read/write)	1184831	1184831	0	0.0
			.bleromro	6342	6342	0	0.0
			.bleromrw	124	124	0	0.0
			.boot2	328	328	0	0.0
			.bss	67601	67601	0	0.0
			.bss_psram	24368	24368	0	0.0
			.comment	48	48	0	0.0
			.data	3952	3952	0	0.0
			.debug_abbrev	1549458	1549458	0	0.0
			.debug_aranges	132744	132744	0	0.0
			.debug_frame	487708	487708	0	0.0
			.debug_info	40736904	40736905	1	0.0
			.debug_line	5291774	5291774	0	0.0
			.debug_loc	3415797	3415797	0	0.0
			.debug_ranges	371896	371896	0	0.0
			.debug_str	3645006	3645006	0	0.0
			.hbn	536	536	0	0.0
			.hbn_noinit	260	260	0	0.0
			.init	342	342	0	0.0
			.init_array	140	140	0	0.0
			.psram	0	0	0	0.0
			.riscv.attributes	47	47	0	0.0
			.rodata	106240	106240	0	0.0
			.rsvd	4	4	0	0.0
			.sha_ocram	72	72	0	0.0
			.shstrtab	304	304	0	0.0
			.stack	2048	2048	0	0.0
			.strtab	579409	579409	0	0.0
			.symtab	175136	175136	0	0.0
			.tcm_data	28	28	0	0.0
			.tcmcode	3358	3358	0	0.0
			.text	964580	964582	2	0.0
		bl702+rpc		0	0	0	0.0
			(read only)	3358	3358	0	0.0
			(read/write)	1272371	1272371	0	0.0
			.bleromro	6342	6342	0	0.0
			.bleromrw	124	124	0	0.0
			.boot2	328	328	0	0.0
			.bss	75633	75633	0	0.0
			.bss_psram	24768	24768	0	0.0
			.comment	48	48	0	0.0
			.data	4504	4504	0	0.0
			.debug_abbrev	1702738	1702738	0	0.0
			.debug_aranges	140968	140968	0	0.0
			.debug_frame	515600	515600	0	0.0
			.debug_info	45431975	45431974	-1	-0.0
			.debug_line	5701205	5701205	0	0.0
			.debug_loc	3616850	3616850	0	0.0
			.debug_ranges	396928	396928	0	0.0
			.debug_str	4069427	4069427	0	0.0
			.hbn	536	536	0	0.0
			.hbn_noinit	260	260	0	0.0
			.init	342	342	0	0.0
			.init_array	156	156	0	0.0
			.psram	0	0	0	0.0
			.riscv.attributes	47	47	0	0.0
			.rodata	120080	120080	0	0.0
			.rsvd	4	4	0	0.0
			.sha_ocram	72	72	0	0.0
			.shstrtab	304	304	0	0.0
			.stack	2048	2048	0	0.0
			.strtab	639953	639953	0	0.0
			.symtab	193424	193424	0	0.0
			.tcm_data	28	28	0	0.0
			.tcmcode	3358	3358	0	0.0
			.text	1036974	1036972	-2	-0.0
cc32xx	lock	CC3235SF_LAUNCHXL		0	0	0	0.0
			(read only)	604426	604426	0	0.0
			(read/write)	204156	204156	0	0.0
			.ARM.attributes	44	44	0	0.0
			.ARM.exidx	8	8	0	0.0
			.bss	197568	197568	0	0.0
			.comment	206	206	0	0.0
			.data	1468	1468	0	0.0
			.debug_abbrev	956917	956917	0	0.0
			.debug_aranges	101056	101056	0	0.0
			.debug_frame	341168	341168	0	0.0
			.debug_info	19511288	19511289	1	0.0
			.debug_line	2664965	2664965	0	0.0
			.debug_line_str	513	513	0	0.0
			.debug_loc	33340	33340	0	0.0
			.debug_loclists	1486884	1486884	0	0.0
			.debug_ranges	4984	4984	0	0.0
			.debug_rnglists	94239	94239	0	0.0
			.debug_str	3068127	3068127	0	0.0
			.ramVecs	780	780	0	0.0
			.resetVecs	64	64	0	0.0
			.rodata	104298	104298	0	0.0
			.shstrtab	265	265	0	0.0
			.stack	2048	2048	0	0.0
			.strtab	480350	480350	0	0.0
			.symtab	287024	287024	0	0.0
			.text	498004	498004	0	0.0
linux	chip-tool-ipv6only	arm64	(read only)	12215404	12215404	0	0.0
			(read/write)	746264	746264	0	0.0
			.bss	34392	34392	0	0.0
			.data	3008	3008	0	0.0
			.data.rel.ro	688000	688000	0	0.0
			.dynamic	560	560	0	0.0
			.got	15672	15672	0	0.0
			.init	24	24	0	0.0
			.init_array	216	216	0	0.0
			.rodata	568688	568688	0	0.0
			.text	9875524	9875524	0	0.0
	thermostat-no-ble	arm64	(read only)	2524324	2524324	0	0.0
			(read/write)	145864	145864	0	0.0
			.bss	56376	56376	0	0.0
			.data	1784	1784	0	0.0
			.data.rel.ro	78168	78168	0	0.0
			.dynamic	560	560	0	0.0
			.got	5448	5448	0	0.0
			.init	24	24	0	0.0
			.init_array	432	432	0	0.0
			.rodata	129848	129848	0	0.0
			.text	2130112	2130112	0	0.0
mbed	lock-app	CY8CPROTO_062_4343W+release	(read only)	6224	6224	0	0.0
			(read/write)	2496432	2496432	0	0.0
			.bss	216296	216296	0	0.0
			.data	5144	5144	0	0.0
			.text	1459116	1459116	0	0.0
nrfconnect	all-clusters-app	nrf52840dk_nrf52840	(read only)	4	4	0	0.0
			(read/write)	1177896	1177896	0	0.0
			bss	155593	155593	0	0.0
			rodata	132920	132920	0	0.0
			text	808660	808656	-4	-0.0
	all-clusters-minimal-app	nrf52840dk_nrf52840	(read only)	4	4	0	0.0
			(read/write)	1123040	1123040	0	0.0
			bss	154749	154749	0	0.0
			rodata	109728	109728	0	0.0
			text	777948	777948	0	0.0
	all-clusters-app	nrf7002dk_nrf5340_cpuapp	(read only)	4	4	0	0.0
			(read/write)	1437592	1437592	0	0.0
			bss	135333	135333	0	0.0
			rodata	228936	228936	0	0.0
			text	779280	779280	0	0.0
qpg	lighting-app	qpg6105+debug	(read/write)	1167608	1167616	8	0.0
			.bss	99632	99632	0	0.0
			.data	856	856	0	0.0
			.text	614708	614716	8	0.0
	lock-app	qpg6105+debug	(read/write)	1136984	1136984	0	0.0
			.bss	94784	94784	0	0.0
			.data	852	852	0	0.0
			.text	584080	584080	0	0.0