[FEATURE] Add image to squad
[FEATURE] Add dummy test for image on squad model
[BUGFIX] Fix wrong type annotation for $image

Fix type for $image by changing "\string" to
"\TYPO3\CMS\Extbase\Domain\Model\FileReference".
[BUGFIX] Fix image config in squad TCA

Use getFileFieldTCAConfig to get a proper config.
[FEATURE] Display the image in squad detail view