add missing tp_as_mapping, tp_as_sequence and tp_as_number functions

[undingen]

Some of our builtin types don't overwrite all of this functions.
This means the perf will be slightly worse because we will call into the slot wrapper which will than do an attribute lookup instead of just calling the function pointer.
One example is our list type which does not initialize the tp_as_mapping function pointers.
They are therefore initialized to slot_sq_length, etc.. while we should overwrite them with custom implementations like list_length.

[undingen]

I added #1198 as an example for such a change.

[sizeoftank]

For example tp_as_mapping in list, I think it could completed by copy the implementation from cpython, right?

[kmod]

Our list object is very similar to CPython's, so that sounds like a good place to start even if there are small things that might have to be adjusted.