Issue #3395961 by Christian.wiedemann: [2.0.x] Add new PropTypes & Sources plugins API

src/Annotation/PropType.php

src/Annotation/Source.php

src/Annotation/UiPatternsSource.php

src/Plugin/Deriver/AbstractPatternsDeriver.php

src/Plugin/Deriver/AbstractYamlPatternsDeriver.php

src/Plugin/Deriver/PatternsDeriverInterface.php

src/Plugin/Deriver/YamlPatternDeriver.php

src/Plugin/Deriver/YamlPatternsDeriverInterface.php

src/Plugin/PatternBase.php

src/Plugin/PatternInterface.php

src/Plugin/PatternSourceBase.php

src/Plugin/PatternSourceInterface.php

src/PropTypeInterface.php

src/PropTypePluginBase.php

src/PropTypePluginManager.php

src/Sdc/ComponentPluginManagerDecorator.php

src/Sdc/UiPatternsSdcPluginManager.php

src/SourceInterface.php

src/SourcePluginBase.php

src/SourcePluginManager.php