postgres: style, factorization and kwargs usage sanitization
postgres states: add and forward all execmod args
postgres: Group and user managment refactoring:

    - stick to postgresql create/alter role
    - handle and detect correctly all roles updates
    - again a whole set of factorization
postgres: support for extensions
postgres: cleanup imports
Merge pull request #9831 from makinacorpus/pgsql

[need review] PGSQL state/mod improvments