WIDEN-398 - Save the asset's external_id alongside ID and version ID (#178)

acquia_dam.install

acquia_dam.module

acquia_dam.post_update.php

src/EmbedCodeFactory.php

src/Plugin/Field/FieldType/AssetItem.php

src/Plugin/Field/FieldWidget/AssetItemWidget.php

src/Plugin/media/Source/Asset.php

tests/src/FunctionalJavascript/CKEditor4IntegrationTest.php

tests/src/FunctionalJavascript/CKEditor5IntegrationTest.php

tests/src/Kernel/EmbedCodeFormatterTest.php

tests/src/Kernel/MediaIntegrationTest.php

tests/src/Kernel/ResponsiveImageStyleTest.php

tests/src/Kernel/TokensTest.php