Update: status code changes, adding "_not" in more places.

Update: status code changes, adding "_not" in more places.

I am not a fan of having so many "_not".
I believe I even made efforts to reduce its usage in the past.

Having said that, there ended up being too many different cases where "_not" makes sense.
I want things to be consistent, so this commit introduces "_not" more thoroughly unless it makes sense not to.

There are also cases where I have prefixes, such as "un" in unknown.
Change this to be consistent with the "_not" logic.
This results in changes like F_unknown -> F_known_not.

Other minor cleanups exist, such as F_interrupted -> F_interrupt.

I expect down the road there will be changes where these "_not" are used in functions where the "_not" is not used.
(Example: it may be that a function returns F_number (with error bit set) on invalid number, but it may be better to now use F_number_not.)