Use JavaScript tooltips for mentions

What does this MR do?

• use JavaScript tooltips instead of plain title for mentions (issue, merge request, snippet, user, group, commit, commit range, milestone)

Are there points in the code the reviewer needs to double check?

Not really.

Why was this MR needed?

JavaScript tooltips look nicer and can wrap.

What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5261#note_13106713, fixes #21500 (closed)

Screenshots

Before	After

cc @DouweM @jschatz1

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• b7879c4d - Use JavaScript tooltips for mentions (!5301 (merged))

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• 4e25544a - 1 commit from branch gitlab-org:master

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• 5748ad09 - Use JavaScript tooltips for mentions (!5301 (merged))

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• 74ddf8e7 - Use JavaScript tooltips for mentions (!5301 (merged))

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@winniehell Nice! For commits, issues, merge requests and snippets, I don't think we need the "Thing:" prefix, since it's pretty obvious from the format/prefix. For commit ranges, I don't think we need the tooltip at all, it doesn't add all that much. Milestones don't really need the tooltip at all, since it will just repeat their name.

What do you think?

@DouweM

For commits, issues, merge requests and snippets, I don't think we need the "Thing:" prefix

For commit ranges, I don't think we need the tooltip at all

Milestones don't really need the tooltip at all, since it will just repeat their name.

(we could display some milestone info like 98% complete, but let's keept that for later)

What do you think?

I will

Marked this merge request as a Work In Progress

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• 94cd6056 - Use JavaScript tooltips for mentions (!5301 (merged))

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• 94cd6056...dc761e3a - 457 commits from branch gitlab-org:master
• 2079b108 - Use JavaScript tooltips for mentions (!5301 (merged))

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• 4865b105 - Use JavaScript tooltips for mentions (!5301 (merged))

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• 6aeb128e - Use JavaScript tooltips for mentions (!5301 (merged))

@DouweM Done, I applied all your suggestions.

@winniehell Nice work! I'll leave this for @jschatz1 to review and merge!

Reassigned to @jschatz1

Unmarked this merge request as a Work In Progress

Added 41 commits:

• 6aeb128e...22c8e21b - 40 commits from branch gitlab-org:master
• 2f7f9e74 - Use JavaScript tooltips for mentions (!5301 (merged))

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• 2f7f9e74...9de37726 - 2 commits from branch gitlab-org:master
• a4e58bb6 - Use JavaScript tooltips for mentions (!5301 (merged))