Merge branch '3516369-regression-on-saving' into '2.0.x'

...ld/src/Plugin/Field/FieldWidget/SourceComponentWidget.php

...i_patterns_ui/src/Element/UiPComponentFormDisplayForm.php

..._patterns_ui/src/Element/UiPComponentFormDisplaysForm.php

src/Element/ComponentForm.php

src/Element/ComponentFormBase.php

src/Element/ComponentPropForm.php

src/Element/ComponentPropsForm.php

src/Element/ComponentSlotForm.php

src/Element/ComponentSlotsForm.php