+1, -1, and other reactions on issues and issue comments

[pgaskin]

There should be +1, -1, and other reactions on issues and issue comments just like GitHub and GitLab.

[jcgruenhage]

@bkcsoft Why are you opposed to this?
Edit: Expressing being opposed to something by using that thing also seems kinda strange :P

[bkcsoft]

@jcgruenhage Because I'm a perhaps? I really have nothing against this. I think I even 👍'd it on the original Gogs-issue 😉 (I pretty much abuse this feature at work, so I'm all for having this in Gitea as well)

[jcgruenhage]

I hoped so, wasn't sure though, so I thought I might ask ^^

[lafriks]

Fixed with #2856