TYPO3 12 compatibility

[koehnlein]

This merge request contains two changes:

1) Replace SignalSlot implementation by Events

There was a remaining SignalSlot implementation left, which did not work in TYPO3 12 anymore and resulted in an error, because \TYPO3\CMS\Extbase\SignalSlot\Dispatcher does not exist anymore.

Looks like the SignalSlot implementation did not work for several TYPO3 reasons. Because the signals already have been removed in the core long time ago. But nevertheless, it's good to have the feature brought back to have correct dimensions for uploaded files.

2) Fix composer constraint

"typo3/cms-core": ">=11.5.0" says "any version since 11.5.0, no matter if it is TYPO3 12, TYPO 13 or TYPO3 99 ... I changed it to the more precise constraint "typo3/cms-core": "^11.5 || ^12.0" which limits it to TYPO3 11.. or 12.. - the same as it is mentioned in ext_emconf.php.

[tmotyl]

Hi Albrecht,
Thanks for the PR!
Please remove the change to composer constraints, as it makes testing the extension with main (upcomming v13) annoying.
We can mention in readme in which TYPO3 versions it was tested, but I would not add a hard limit to v12 only.

[koehnlein]

@tmotyl I did it.

I don't think, it's a good idea. But your repository - your rules ;-)

[tmotyl]

Thanks
Have you tested the changes in v11 too? or is this change only for v12 ?

[koehnlein]

Manually tested in TYPO3 11 and 12