Merge branch '3469665-prop-types-tests' into '2.0.x'

src/Plugin/UiPatterns/PropType/BooleanPropType.php

src/Plugin/UiPatterns/PropType/IdentifierPropType.php

src/PropTypeConversionTrait.php

...omponents/prop_types_tests/prop_types_tests.component.yml

...tterns_test/components/test-component/test-component.twig

...c/Kernel/PropTypeNormalization/AttributesPropTypeTest.php

.../src/Kernel/PropTypeNormalization/BooleanPropTypeTest.php

tests/src/Kernel/PropTypeNormalization/ComplexTest.php

...src/Kernel/PropTypeNormalization/EnumListPropTypeTest.php

tests/src/Kernel/PropTypeNormalization/EnumPropTypeTest.php

.../src/Kernel/PropTypeNormalization/EnumSetPropTypeTest.php

...c/Kernel/PropTypeNormalization/IdentifierPropTypeTest.php

tests/src/Kernel/PropTypeNormalization/LinksPropTypeTest.php

tests/src/Kernel/PropTypeNormalization/ListPropTypeTest.php

...s/src/Kernel/PropTypeNormalization/NumberPropTypeTest.php

tests/src/Kernel/PropTypeNormalization/SlotPropTypeTest.php

...s/src/Kernel/PropTypeNormalization/StringPropTypeTest.php

tests/src/Kernel/PropTypeNormalization/UrlPropTypeTest.php

.../src/Kernel/PropTypeNormalization/VariantPropTypeTest.php

tests/src/Kernel/PropTypeNormalizationTestBase.php