Customization improvements

[shilangyu]

Expand customization with new comment and post styles, and more user choice relating to the look of the app.

• [ ] User has 2 post styles to choose from: compact and card
• [ ] Comments have the following customization options:
  • [ ] 2 indent styles: lines and bars
  • [ ] 2 button styles: hidden and always visible
  • [ ] swipe gestures assignable to user-chosen action
• [ ] User can turn on or off post trimming and select how many lines should be trimmed
• [ ] User can select default comment sorting
• [ ] User can select default inbox sorting
• [ ] User can choose whether to use raw username instead or display name
• [ ] User can choose whether to use raw community name or display name