Re: pgAdmin 4 - gettext usage fixes

Hello,
I fixed using gettext function and add more usages for translations,
specifically:

- fixed usage gettext('') instead of _('') in javascript files
- fixed usage gettext('') instead of `${gettext('')}` in javascript
files, because "pybabel extract" not support extracting from this
syntax
- added a lot of gettext for support translations

Diff file is attached.

Best regards,

Libor M.

E-mail: liborm85@gmail.com
GitHub: https://github.com/liborm85