Add separate database table for LaTeXML (step 5)

Currently the PNG and the LaTeXML rendering mode
use a common table in the database. If both rendering
modes are allowed in a wiki simultaneously this causes
problems, because the fields are continuously overwritten.

This is patch changes the logic of the rendering
engine to use the specific database.
The caching logic is now simpler to understand.
A entry is written to the database if the changed field
of the MathRenderer class is true. Is is triggered by the
setters of the database relevant fields.


Bug: 65522
Change-Id: Ief9de889b9292b21c9d1529a8b1797f38196edad