Add support of NOT REGEXP operator to PostgreSQL

Problem/Motivation

We have support LIKE and NOT LIKE operators. But we do not have the opposite operator to REGEXP, namely, the NOT REGEXP (negated regular expression).
It can blocks others feature requests, eg. #2853188: [PP-1] Views string filter negated regular expression

Proposed resolution

Let's add this antagonist for the complete picture of the world.

Remaining tasks

Add NOT REGEXP + test coverage like REGEXP.

User interface changes

API changes

Data model changes