Add type arguments for generic classes

[nanewalt]

Chore

Update client methods to mirror postgrest return type hints

Describe the chore

Methods in both sync & async clients specify generic return types without type arguments, resulting in linter warnings.

def from_(self, table_name: str) -> SyncRequestBuilder:
        """Perform a table operation.

        See the `table` method.
        """
        return self.postgrest.from_(table_name)

query = supabase.from_("foo")    # Type of "from_" is "(table_name: str) -> SyncRequestBuilder[Unknown]" [reportUnknownMemberType]

Even with type hinting on the variable, we get a similar error

class Foo(BaseModel):
    ...

foos: list[Foo] = supabase.from_("foo").select("*").execute().data  # Type of "data" is "List[Unknown]" [reportUnknownMemberType]

The underlying postgrest methods do specify type arguments, but this is hidden behind the type hints in the supabase client. There seem to be two possible resolutions here:

1. Remove type hints from methods in the supabase clients and allow underlying postgrest type hints to propagate

def from_(self, table_name: str):
    ...

2. Add type arguments to existing generic return types in the supabase clients

_ReturnType = TypeVar("_ReturnType")

def from_(self, table_name: str) -> SyncRequestBuilder[_ReturnType]:
    ...

I tend to prefer option 1 since these methods are simple wrappers - if postgrest-py updates their return types in the future, why have the burden of updating those here as well?

Additional context

postgrest-py from_ method

[grdsdev]

@silentworks, what do you think about these suggestions?

[silentworks]

I'm going to test this out and get back to you on this issue.

[silentworks]

Yeah the issues stated by @nanewalt are correct. I've created a PR to fix the issue.