Integrate Meta Generation into Sevntu for eclipse-cs usage

[rnveach]

Identified at #857 (comment) ,

eclipsecs-sevntu-plugin no longer works correctly since eclipse-cs migrated to the new metadata model.

Although 1.40 SevNTU installs into Eclipse, the configuration menu is still empty.

A manual port was started at #821 , but this was trying to manually create the XML files instead of trying to hook into Checkstyle's automated system.

It makes more sense we try to hook into Checkstyle's automated system, MetadataGeneratorUtil.

Identified at #857 (comment) ,

For Checkstyle's meta generation to be integrated into sevntu, sevntu has to redo all it's javadocs to the format checkstyle wants. Checkstyle currently won't support any Checks that don't match this format and prints nothing by default (no descriptions or any properties) to the XML files it tries to generate.

We need to rewrite all Sevntu javadocs to the new format and then implement the necessary functions for this to be automated for future changes.

[rnveach]

Changes need to be made to both Checkstyle and Sevntu for full integration.

An example beginning can be seen in the following branches:
https://github.com/rnveach/checkstyle/commits/metadata_extension
https://github.com/rnveach/sevntu.checkstyle/commits/metadata_extension

I have also started issues in Checkstyle for some improvements related to this integration.
checkstyle/checkstyle#10747
checkstyle/checkstyle#10748
checkstyle/checkstyle#10749
checkstyle/checkstyle#10756

[rnveach]

Integrating MetadataGeneratorUtilTest requires atleast checkstyle 10.1.

[romani]

Eclipsecs 10.3.3 now available