Fix #1033 as well as other (potential) similar issues

Added type="button" (and type="submit" where applicable) to buttons to prevent <button> acting as a submit (which is default, thanks w3c), i.e. it would be "clicked" if enter is pressed.

Most notably - #1033 (closed) fixes OTP entry and recovery forms and fixes hitting "enter" in subject line input triggering the emoji picker.

Also did small change to EmojiReact button's classnames for consistency and tija's sake so it's easier to write userstyles for.

the type=button changes are fine, but I'll have to double check the react button change, there's some really fiddly easy-to-break stuff there

yep changing the classes messes up the hitboxes

I'll leave out that commit for later then

enabled an automatic merge when the pipeline for 982c799b succeeds

mentioned in commit 6f3acb3c

merged