Fix gitlab-psql and gitlab-geo-psql to default to known database based in Omnibus config

The following discussion from !2487 (merged) should be addressed:

• @stanhu started a discussion: (+2 comments)

  Could we default to gitlab_geo_production as the default database?

By rewriting it in ruby, we can use something like OptionParse to handle -d database and default to gitlab's one when nothing is specified. This would allow us to run just gitlab-psql and get into gitlabhq_production or override it to -d somethingelse

It looks like it's possible to add parameters and override then after so the later takes precedence. This allows us to use current bash script + some modifications in gitlab-psql-rc and geo equivalent