Merge #11842

Merge #11842

11842: Fix duplicate type mismatches with blocks r=flodiebold a=flodiebold

E.g. when there's a type mismatch on the return value of a function. To fix this, we have to return the expected type as the type of the block when there's a mismatch. That meant some IDE code that expected otherwise had to be adapted, in particular the "add return type" assist. For the "wrap in Ok/Some" quickfix, this sadly means it usually can't be applied in all branches of an if expression at the same time anymore, because there's a type mismatch for each branch that has the wrong type.

Co-authored-by: Florian Diebold <flodiebold@gmail.com>