Change the displayed controls in the TAS Input window when the
controller's extension (including MotionPlus) is changed.

This previously required restarting Dolphin after the attachment was
changed, as the controls were never updated after the WiiTASInputWindow
was created at Dolphin startup.

SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.

NumericSettings support a max, so let's use it.
It might not do much now, but the max and min values will be used to give visual feeback
in the UI in one of my upcoming input PRs