Make SideComments.js work on mobile

SideComments.js currently has a bug where "touching" out of the comments section doesn't close them. Also, there are weird glitches where elements flash on the screen when opening and closing. This PR is to finalize making SideComments.js completely mobile friendly.

- [ ] ~~Use swipe gestures for showing and hiding the comments in addition to tapping the comments marker.~~ (Skipped)
- [ ] ~~Get comment forms working on mobile (or remove comment submission on mobile for now and add at a later time)~~ (Skipped)
- [x] Use taps for the comments marker instead of click bindings.
- [x] Ensure comment marker is still touchable to close comments.
- [x] Make sure spacing and layout is not broken when showing or hiding the comments.
- [x] Fix any glitches with elements flashing, animation not working, etc.
  - [x] Fix "element sizing" bug when comments are first shown after swipe.
- [x] Ensure the comment marker for adding new comments is accessible without hover.
- [x] Fix issue where opening comments scrolls to top of page rather than staying in the right spot scrolled down the page.