Refactor input config and reporting (CHANGES INPUTS)

Note that this is a change which changes which inputs and in what order.

This commit is a significant refactor of the code responsible for
configuring and reporting inputs from the devices. The original driver
code was designed around the Joy-Cons and then the Pro Controller, which
had enough in common that they could share several abstractions. With
the addition of the NSO controllers, these abstractions no longer make
sense.

I've been planning to do this for a while. Below is a list of changes.

* The `input_dev` field was sometimes called `input` and sometimes
  called `dev`. I've changed it to `idev` throughout to be consistent
	and to match with `hdev`.
* `nx_con_device_is_any_joycon` no longer has any use since the
  abstractions which apply to both Joy-Cons are gone.
* Some functions have been renamed (like `nx_con_parse_imu_report`) to
  be slightly more consistent with the overall pattern. There are
	probably more renames I'd like to do.
* `nx_con_parse_report` was broken up into several functions. This forms
  a pattern that mirrors the one I added in `nx_con_input_create`.
* `nx_con_input_create` was also broken up, forming the pattern I just
  mentioned in the last point. (It stands to reason this pattern would
	serve to allow me to break this code into several source files, but I
	am not eager to do that yet.)
* Some reformatting was done (alignment fixes and such).
* BREAKING CHANGE: Home and Capture buttons were all mapped to `BTN_0`
  and `BTN_1`, respectively.
* FIX: The right Joy-Con SL and SR buttons were not properly configured.
  This has been corrected.
* Some debugging statements were removed.