[!!!][TASK] Remove legacy TypoScript files
[!!!][FEATURE] Drop support for TYPO3 v9, add support for TYPO3 v12.2
[TASK] Add decoding attribute to template
[TASK] Setup modern DI
[TASK] Modernize test suite
[BUGFIX] Changes processing instructions for fallback image (thx @naturefund-falk)
[BUGFIX] Fix #45: bad srcset is generated for some images (thx @dmitryd)
[FEATURE] Placeholder image for lazyloading (thx @tillschweneker, @moe2k)
* Compatibility with TYPO3 9 (mostly autoloading changes)
* Fall back to simple image tag for svg images (list of file extensions that trigger this can be configured)
* Add action to demo plugin to be able to test various ViewHelper calls
* Make sure that extension behaves correctly when `[GFX][processor_allowUpscaling]` is disabled (@naturefund-falk)
* Add `lazyload` attribute to both ViewHelpers to allow image lazyloading via JavaScript (@oliverbaran)
* Add TypoScript constant to disab