LUCENE-10261: Remove preset analyzer panel from Luke Analysis UI.

[mocobeta]

This removes "Preset analyzer" panel from the Luke Analysis UI so that we can throw away old reflection hacks that prevent adopting Java module system.

Analysis UI now only supports "Custom analyzer" panel - that definitely covers the whole functionality of dropped "Preset analyzer".

[dweiss]

Hi @mocobeta ! Do you really want to remove it entirely? Maybe there is a way to make it work, somehow? This is not really a showstopper for the 9.0 release anyway - maybe we can figure out how to do it with modules later on?

[mocobeta]

Personally it is sufficient for me to have Custom Analyzer in the Analysis UI, and I can't remember why I implement it.
I don't think we should waste developers' time on the problematic UI. It is easy to re-implement the same component once we come up with another way to enumerate provided Analysers (SPI?) in some module-friendly ways.

[dweiss]

I don't know if you saw my comment here - https://issues.apache.org/jira/browse/LUCENE-10261 - this is quite mind-bending what happens in there. :)

[uschindler]

I would just change the defaults. Show the custom view first and only allow to fallback to hard coded analyzers.

[uschindler]

Is this class still in use at other places in Luke?

[mocobeta]

Yes, unfortunately. This is still used to list available directory implementations (when opening an index).
In 9.0, it still works - some Directorys that does not reside in lucene-core was gone from the list though.

lucene/lucene/luke/src/java/org/apache/lucene/luke/app/desktop/components/dialog/menubar/OpenIndexDialogFactory.java

Lines 260 to 263 in d973e50

	private String[] supportedDirImpls() {
	// supports FS-based built-in implementations
	ClassScanner scanner = new ClassScanner("org.apache.lucene.store", getClass().getClassLoader());
	Set<Class<? extends FSDirectory>> clazzSet = scanner.scanSubTypes(FSDirectory.class);

[mocobeta]

@uschindler @dweiss
There are only three FSDirectory implementations (in lucene-core) and it isn't likely to be added as Analyzers. Maybe we should hard code the class names (FQCNs) here, then remove ClassScanner from the module?

[uschindler]

Yes. There may only come a new mmapdir in future, but nothing else inside lucene. We have more directories in Sandbox or misc module, but those are special (wrappers on top of others).

[mocobeta]

Cleand it up in #480.