fix #12864 static params were mutating arg types during sigmatch; fix #12713 ; refs #13529

[timotheecour]

• fix TimeFormat() should raise an error but craches at compilation time #12864
• fix A few bugs related to static parameters #12713
• refs type Foo[T: static] = object doesn't work; type Foo[T] = object is buggy when instantiated with static generic arg #13529, almost closes it by providing a better alternative:
  type StaticParam*[value: static type] = object
  instead of
  type StaticParam*[value] = object
  which makes it more typesafe, see tests in tests/statictypes/tstatictypes.nim

Note: the change to typetraits.nim was necessary after the fix for #12864 but is a good change anyways.

• More generally, static[T: static type] is the correct way to provide a static param of any type

• CI failure unrelated => recent commit broke Nim CI inim-repl/INim#63 (was fixed upstream after i reported it)

[Clyybber]

Would also fix #12713 .
Not sure if its the right way to fix this though, as I was under the assumption that sigmatch relies on this mutation (which is the culprit here).

[timotheecour]

Would also fix #12713 .

indeed, thx for pointing it out, I verified it fixes all cases and added test cases for the last 2 examples (avoiding dependency of 1st one)

Not sure if its the right way to fix this though, as I was under the assumption that sigmatch relies on this mutation (which is the culprit here).

all other cases don't mutate, I think this was just a bug

[Araq]

Thank you! Excellent work!