[12.x] fix(postgres): missing parentheses in whereDate/whereTime for json columns

[saibotk]

In #12341, the cast to ::date was added to whereDate.

This leads to an error with PostgreSQL when passing in json column selectors. For example:
->whereDate('result->created_at', DB::raw('NOW()')) will throw a syntax error for type date. The same is true for the whereTime function with its ::time cast.

To fix this, we need to wrap the column identifier in parentheses, when they are json paths.

Current SQL output:

select * from "users" where "result"->>'created_at'::date = NOW()

Correct SQL output with this commit:

select * from "users" where ("result"->>'created_at')::date = NOW()

I opted to only add the parentheses when the column is a json path, as this is the only case where the cast is necessary.
This is at the cost of another str_contains check. Which should be fine but we could also opt to just always add the parentheses if you want to.

Note: I checked all other functions and these two should be the only ones that are affected by this. The whereBasic also does cast to ::text but PostgreSQL did not complain on text casts.