[Improvement] Add Abstract class(ABC) for MeasurementControl.settable() and MeasurementControl.gettable()

Description

Add abstract class that defines the interface for:

class BaseParameter(object):
    @abstractmethod
    def prepare(self) -> None:
        pass

    ...

• Property: .batched (default=False)
• Method: .prepare() -> None
• Method: .finish() -> None

Motivation

Due to the nature of quantify as a software framework it should have defined clear interfaces for its users.

The input parameter for MeasurementControl.settable(...) and MeasurementControl.gettable(...) is clearly defined. settable_pars or gettable_pars is a list or tuple.

from typing import Union, List
def settables(self, settable_pars: Union[List[BaseParameter], Tuple[...] ]):
   ...

def gettables(self, gettable_pars:  Union[List[BaseParameter] ...):
   ...

Utimately improving:

• autocompletion
• readability
• ability to reference to in the docs