feat(Reactions): add All button

[DorraJaouad]

☑️ Resolves

• Fix Not possible to see all reactions #7139

🖌️ UI Checklist

🖼️ Screenshots / Screencasts

Ordered historically

🏚️ Button	🏡 Modal

🚧 Tasks

TODO:

• Guest icon should not have "G" if it refers to "guest"

• Code review

• Design review

🏁 Checklist

• 🌏 Tested with Chrome, Firefox and Safari or should not be risky to browser differences
• 🖌️ Design was reviewed, approved or inspired by the design team
• ⛑️ Tests are included or not possible
• 📗 User documentation in https://github.com/nextcloud/documentation/tree/master/user_manual/talk has been updated or is not required

[Antreesy]

Nothing blocking from my side, all nicely done. Let's wait for the design input

[marcoambrosini]

Nice one! I would agree with @Antreesy suggestion to use the heart character with a counter like telegram does.
I would also remove the border between the tabs and the list in the dialog

[nickvergessen]

Seeing it the first time in use now, I think we should change 2 things:

• Hide the button similarly like the "Emoji plus" when the message is not hovered/focused
• To avoid jumping with above change, move the heart to the end between the reactions and the "Emoji plus"