Improve repository-provider selection UX (when adding a new Project)

[jankeromnes]

When adding a new Project, you need to select a repository, and first you need to select which Git provider you'd like to view repositories from.

Current UX

There is an option at the bottom of the repository-owner dropdown to switch to a different Git provider.

Also, PR #5474 added a more visible change link next to gitlab.com.

Suggested improvements

#5474 (comment)

suggestion: I think using just the verb change could go unoticed and confuse some users. Following the discussion in #5120 (comment) and the second iteration of the designs for repository selection in #4948, we could use a more verbose message here or below the repositories list. What do you think?

Approach A	Approach B	Second iteration for repository selection

[jankeromnes]

I think using just the verb change could go unoticed and confuse some users.

Personally (but this is very subjective), I find this link to be in the most noticeable spot, and I don't think it would confuse me.

When an app is in an unexpected state (e.g. it's showing me GitHub repositories when I actually want to select a GitLab repository) I tend to look for clues as to why it's in the wrong state. Here, that clue is the bold github.com text in the sub-title. Immediately after, I look for a way to change this wrong element. In the previous UI, I was stuck, because there is no control next to the "wrong" information (I eventually stumbled upon the link at the bottom of the dropdown by accident, but it's so "far removed" from the wrong element that I didn't initially find it). Having a direct control to "fix" the "wrong" information (i.e. github.com --> gitlab.com) is what I personally expect in this situation.

However, the "easiest choice in the world" is always slightly worse than "no choice needed by design". Here, if we can go for Second iteration for repository selection, that resolves 100% of the issue for me (i.e. no need to pick a provider, or even understand what a provider is in the first place -- just select the repository from a combined list 👍).

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.