Fix static assert in CMS. Fix CMS OSD element entries.

[pieniacy]

So the whole build fails when using USE_MSP_RC_OVERRIDE, because a static assert incorrectly checks for the cms array length.
Additionally, things recently added to osd items enum missed their entries in cms.

This should fix both issues along with a few minor things along the way.

[shellixyz]

Oops I didn't see you already made a PR which fixes the CMS OSD menu so I have made one too #6930 . The static_assert stuff should just be removed I think, there are too many cases to take into account now

[pieniacy]

Sure, no problem. I agree that such assert is a very selective test and it is ok to just delete it. Feel free to close this PR.

btw. there is kinda related thing, also from me, also not answered, here: #6799

[stale]

This issue / pull request has been automatically marked as stale because it has not had any activity in 60 days. The resources of the INAV team are limited, and so we are asking for your help.
This issue / pull request will be closed if no further activity occurs within two weeks.

[stale]

This issue / pull request has been automatically marked as stale because it has not had any activity in 60 days. The resources of the INAV team are limited, and so we are asking for your help.
This issue / pull request will be closed if no further activity occurs within two weeks.

[shellixyz]

Already fixed in #6930, closing