[server.rqlannotation] rename SQLGenAnnotator to RQLAnnotator This class is in charge of annotating the RQL syntax tree with various bits of information, like (in)variance, use of full-text-index, etc. It is a needed step before the generation of SQL, but does not touch SQL directly. Hence RQLAnnotator seems a better name.

Tests: pytest
Depends:
 @builddeps@,
 # Uncomment  if the tests require database access
 #python3-cubicweb-postgresql-support
Restrictions:
 allow-stderr,
 # Uncomment if the tests require database access
 #isolation-container,