Improve and unify non-existing git commit user e-mail tooltip

[silverwind]

1. Add e-mail tooltip over non-existing username in commit view:

2. Replicate the same behaviour into commit list and latest commit:

Now all three render the same tooltips. There is an existing e-mail tooltip over the avatar as well and this continues to work as-is.

[lafriks]

I don't think showing email in the UI is a good idea, maybe only for authorized users

[silverwind]

It was already shown previously as a tooltip on the avatar in the commit view, but was not consistent.

[silverwind]

And yes, I agree it should be hidden for anonymous users, but imho thats a separate topic and we need to validate all places where we pass these addresses to the frontend.

[silverwind]

I think I could actually try to fix this at least in these 3 places, make a subtemplate for "avatar and username" and do the logged in check there, wip until then.

[lunny]

Since the repository is public, it can be accessed freely. Anyone can clone it and obtain the email information locally anyway.

[silverwind]

I guess it has a small benefit against scrape bots.