feat: encode source address correctly in gateway

[mustermeiszer]

Description

The address that we are receiving from EVM chains is a utf-8(hex(address)) encoded byte bloob. This was an issue before because we expected it to be just an [u8; 20].

Changes and Descriptions

• update parsing of account from Axelar
• utility function for both precompile and gateway

Checklist:

• I have added Rust doc comments to structs, enums, traits and functions
• I have made corresponding changes to the documentation
• I have performed a self-review of my code
• I have added tests that prove my fix is effective or that my feature works

[wischli]

LGTM apart from two minor details which can also be ignored.

[wischli]

CR: We are importing hex without std here but not enabling the std feature below.

[wischli]

Nit: Formatting off.

Suggested change

	// NOTE: Axelar simply provides the hexadecimal string of an EVM
	// address as the `sourceAddress` argument. Solidity does on the
	// other side recognize the hex-encoding and encode the hex bytes to
	// utf-8 bytes.
	//
	// Hence, we are reverting this process here.
	// NOTE: Axelar simply provides the hexadecimal string of an EVM
	// address as the `sourceAddress` argument. Solidity does on the
	// other side recognize the hex-encoding and encode the hex bytes to
	// utf-8 bytes.
	//
	// Hence, we are reverting this process here.

[wischli]

Thanks for applying my nits!