New Help menu in top navigation

This is the implementation issue for related ~"product discovery" in https://gitlab.com/gitlab-org/gitlab-ce/issues/48924.

Problem to solve

We're proposing a number of additions to the profile dropdown:

This is in addition to "Help".

4 of the items mentioned above don't seem to belong to this menu. The profile dropdown should organize options that directly relate to me as a user; my user info, Profile, Settings, Sign out, and status all match this pattern. The rest do not.

We should consider a new place for these "meta" items that all relate to interacting with and understanding your GitLab instance.

Possible option

Possible options have been discussed here, based on a UX research.

Solution

Display a new "Question" icon (icn/question) next to the user menu that opens a dropdown which (in the future) will contain these options:

We also remove the external-link icon, from rows like Contribute to GitLab.

All these options will be removed from the profile dropdown, which will now only have the following elements:

Name / @username
View profile
Settings
Sign out

There will be a separator above Sign out.

Help dropdown	User dropdown

The width of the new dropdown will be the standard 240px.

Iteration

Since not all the options that will go in this dropdown are currently available, the design will need to be tweaked in the meantime.

Step 1

We will start without a separator between the Help row and the rest of the elements.
There will always be a separator between Get a free instance review and the elements above. This row does not show up on all installations.

If we do not offer an instance review, the content of the dropdown will be: