Compact mode: vertically center emoji picker on the message, and bring previous line height and font back

I feel like the fonts and spacing were already pretty ideal how they were before and didn't need a change; the emoji picker is almost cool but being offset from the message is just a total fail, and I know slack did it first, but it's always been hard to use there too. I like being able to set a spacing between message groups, but I want the default spacing to be less, like how it was before. I do think the new emoji picker hover is cool in some ways though and improves a thing about how it was a little hard to find the add emoji button for me before - it just is going to be hard to add it to the right message now, because it's offset from the message.