Individual management page for recordings

[daronco]

Currently the list of recordings in the management section is at /bigbluebutton/recordings. This page is a simple adaptation of the views in BigbluebuttonRails, and it could be improved a lot.

The idea is to have a page that will be shown as an individual tab in the management section, similar to the tabs for the list of users and the list of spaces. This list would be visually similar to the lists of spaces and users, but showing information relevant to the recordings (ID, room name, created at, etc), would be paginated and would be searchable/filterable.
It should also include buttons to act over a recording, including things like publish, unpublish, destroy, edit, view playback types, etc.

[daronco]

Another option that should be available in this view is an "update" of the recordings, that would send a getRecordings to the server for this specific recording and update it in the database with the info received.

There are already fetch_recordings routes for servers and rooms, but not for recordings.

[daronco]

The last comment can be ignored in this issue, it has now its own issue: #899.