[DOCS] mention the type of caches that warmers load
Fix: VerboseProgress(PrintWriter) does not set the writer
Tests: move plugin dir to plugins dir

We should be consistent in our naming for classes and resources.
Update api & Indices stats: fixed version checks for no-op updates which got in after 1.3 was released

Also added basic bw comp test for indices stats api.

Relates to #6822
A content decompressor that throws a human readable message when
compression is disabled and the user sends compressed content.
Add GroovyCollections to the sandbox whitelist

Also clarify in the docs that changing the whitelist/blacklist settings
replace the list, they don't add to it.

Fixes #7089
Fixes #7088
Forbid index names over 100 characters in length

Fixes #4417
Count name bytes instead of length, add test