XRENDERING-6: Id are not unique when included document or macro content has the same headers as the top document

* Add methods to set the id of headings and images to be able to change
 them when including or displaying a document.
* Make the id generator thread-safe.

XRENDERING-6: Id are not unique when included document or macro content has the same headers as the top document

* Extend the parser APIs to be able to pass an id generator.
* Re-use the id generator when parsing link and figure caption content.
* Use the id generator of the XDOM in DefaultMacroContentParser.
* Add tests.

XRENDERING-651: Automatically generate ids for images

* Remove useless Javadoc comment.

* Replace ImageBlock.equals by standard implementation. This doesn't
treat subclasses as equal.

* Fix Javadoc comments.

* Generate ids similar to headings in DefaultXWikiGeneratorListener for
WikiModel-parsers and XWikiGeneratorSink in the Doxia parser.
* Add a new id attribute to ImageBlock.
* Add a new version with id parameter to ImageListener.onImage.
* Add retro-compatibility support for onImage to
AbstractChainingListener.onImage.
* Implement the new onImage method in all generic listeners.
* Output the id in the XHTML renderer and ignore the generated id in the
 XHTML parser.
* Adapt all integration tests to expect the new generated id.
* Migrate EventsChainingRendererTest to Junit5.
* Add a unit test for wrapping listener.

This was a leftover of XRENDERING-629.

* Properly handle metadata blocks.
* Remove useless continue-statements.
* Migrate test to JUnit 5.
* Add a test with actual XWiki syntax to avoid a regression.

XRENDERING-628: Treat images that are alone in a paragraph and have a label as captioned figure

* Print empty parameters when the next event is a begin format event with non-empty parameters.

The test is actually passing, the space just needs to be escaped accordingly.

* Undo parser changes. We instead use the existing nesting support via escaping.
* Make sure the label of references is properly escaped, this fixes verbatim link syntax in captions not being escaped. The new code escapes more than strictly necessary to make sure escaping works reliably.
* Remove hacks for link label escaping.

* Detect paragraphs with a single image with label and transform them into a figure in the parser.
* Handle figure and figure caption events in the XWiki syntax renderer.
* Introduce a chaining listener to analyze the content of the figure.
* Add tests to test the new syntax.
* Extend parser to allow nested links if it ends with an image reference.
* Transparently add and remove a class="image" parameter.

* Switch to HTML 5 when the output syntax is HTML 5 or annotated HTML 5.
* Change the default output syntax to HTML 5.
* Do not assume that the rendering context has the target syntax set.
* Adapt tests.
* Migrate the unit test to Junit 5.
* Support "htmlmacro+xhtml/1.0" as alias for "xhtmlmacro/1.0" to avoid further special handling for the old hint.
* Indicate the actual HTML target syntax in the result.

* Change since-comments to 14.1RC1.
* Fix parent version.

* Add missing XHTML_5 entry to Syntax class.

* Rename XWikiSpanTagHandler to XHTML5SpanTagHandler to avoid confusion.
* Change HTML5 to XHTML5 in a few cases.

* Add missing unstable-annotations and since-comments.

* Add a dependency to the xhtml/1.0 test-jar.

* Create a new XHTML 5 parser module.

* Add WikiModel events for figure and figure captions.
* Add a (basic) parser for HTML 5.
* Add a (basic) parser for XHTML 5.
* Handle the figure and figcaption tags.
* Handle span-tags with monospace and verbatim content.
* Add several tests for monospace content.
* Add a test case for parsing figure and figure caption.

* Check in LookaheadChainingListenerTest that all methods are
  implemented, forward the correct event and give the correct lookahead.
* Added test case for CompositeListener.

* Save parameters in endListItem.
* Add a QueueListenerTest.

XRENDERING-644: AbstractChainingListener has no compatibility mode for endListItem without parameters

* Add missing version-annotation

XRENDERING-644: AbstractChainingListener has no compatibility mode for endListItem without parameters

* Stop the propagation to the parent once a class with both methods has been found, see also XRENDERING-646.
* Rewrite using streams to reduce cognitive complexity metric.
* Do not use separate compatibility for begin and end of list items.

XRENDERING-644: AbstractChainingListener has no compatibility mode for endListItem without parameters

* Fix name of test case.