The old pages UI was not intuitive and often led to questions like:
* How do I bind multiple controllers to a single input?? (failure to
discover)
* I have a ghost input that won't go away, how do I fix this? Is this a
bug? (non-intuitive UI - there are too many pages and finding out where
each binding is potentially requires scrolling through 100 pages)
* Potential perf issue - user binds too many by accident, or puts
bindings all the way in page 99, requiring us to walk each element in
the vector, wasting precious CPU cycles during an input poll.
This PR removes the multiple pages, and puts everything on a single
page, showing multiple binds in a tree structure.
It also puts a hard limit on how many alternate bindings can be made (8
for buttons, 16 for lights), though if the user has configured more in
older version they will be respected.
## Description of change
* Add a red `x` button to replace `Clear` button in binding tabs
(Buttons/Analog/Lights).
* Add a gray `x` button to replace `Clear` button in options tabs next
to input widgets
* Add helper for truncating text and adding ellipsis (...) to deal with
text overflow in tables.
* Reword some UI text for clarity
## Link to GitHub Issue, if one exists
n/a
## Description of change
Add `Help` menu.
Move Licenses and About dialog under Help.
Add links to the wiki.
Make game selection drop-down slightly wider to make better use of space
that has been freed up.
## Testing
tested in cfg (with/without game), and in-game overlay
bicarus