Fix filter api issue with 'any condition' and text search

A filter combining some criteria and a text search with 'any condition'
results in a cartesian product, which has the potential to bring down
the site as the RDBMS eats up all available resources.

The root cause of this behavior is joining the bug_text table with a
from clause and setting the join's criteria in the query's where clause,
without taking consideration the operator's precedence (AND/OR).

This commit resolves the problem by using a JOIN clause instead, which
makes the query cleaner.

Fixes 0015573