[HOLD for payment 2023-05-22] Add mentions auto-completion

[puneetlath]

As part of the mentions project, we will be adding auto-completion for mentions by using the @ symbol. We should break this up into at least two PRs:

1. Adding the generic AutoCompleteSuggestions component and refactoring the existing EmojiSuggestions to use the new AutoCompleteSuggestions component
2. Adding MentionAutoSuggestions which will also use the AutoCompleteSuggestions component

The details of the implementation are described in the doc here.

[MelvinBot]

Current assignee @puneetlath is eligible for the NewFeature assigner, not assigning anyone new.

[szebniok]

Hey, I'll be working on this.

[puneetlath]

PR 1 is up!

[puneetlath]

Assigning @0xmiroslav as C+

[melvin-bot]

Reviewing label has been removed, please complete the "BugZero Checklist".

[melvin-bot]

The solution for this issue has been 🚀 deployed to production 🚀 in version 1.3.13-5 and is now subject to a 7-day regression period 📆. Here is the list of pull requests that resolve this issue:

• Add mention suggestions #18469

If no regressions arise, payment will be issued on 2023-05-22. 🎊

After the hold period is over and BZ checklist items are completed, please complete any of the applicable payments for this issue, and check them off once done.

• External issue reporter
• Contributor that fixed the issue
• Contributor+ that helped on the issue and/or PR

As a reminder, here are the bonuses/penalties that should be applied for any External issue:

• Merged PR within 3 business days of assignment - 50% bonus
• Merged PR more than 9 business days after assignment - 50% penalty

[puneetlath]

@0xmiroslav sent you an offer in Upwork: https://www.upwork.com/nx/wm/pre-hire/c/8577561/offer/24557708

[puneetlath]

All paid. Thanks again everyone!

[0xmiros]

@puneetlath sorry, this issue is linked to 2 PRs: #18024, #18469

[puneetlath]

Ah whoops. Well it's already paid!

[0xmiros]

#18024 - this one too?

[puneetlath]

Ahhh sorry. I see the mistake. Sent you another contract. (https://www.upwork.com/nx/wm/pre-hire/c/8577561/offer/24664071)

[puneetlath]

Ok all paid for real now.