Add admin page to list all available projects in DB

[Bounga]

It is one of the requested feature of #39

This PR adds a page that list all available projects in DB and that is only available to logged in users.

I decided to sort it alphabetically and add bootstrap styling since it was already available.

It looks like this:

[cllns]

:+1: Cool! Can you provide a screenshot? So when anyone comes back to this PR, it'll be clear what changes are made just be scanning it. (Editing the first post would be best)

[Bounga]

@cllns Here it is

[davydovanton]

checked prod instance. All works perfect. Great work 👏

[dsalahutdinov]

:+1: