load_script type checking - allow `np` datatypes in `cset` / `PVValue`

As a user on MERLIN I would like the following snippet to pass type checking:

import numpy as np
from genie_python import genie as g

def runscript():
    for psi in np.arange(30,130,10):
        g.cset("Rot", psi, lowlimit=psi-0.1, highlimit=psi+0.1, runcontrol=True)

It currently fails with:

E: Argument of type "signedinteger[Any]" cannot be assigned to parameter "args" of type "PVValue"

PVValue should also include np types

Acceptance criteria

• Above snippet passes type checking