Annotate bPoint.py module

[roberto-arista]

Hey there!

Here's the PR for bPoint.py annotations.

A few notes:

• I get a Signature of "_reprContents" incompatible with supertype "BaseObject" error on _reprContents()
• I also get a Incompatible types in assignment (expression has type "None", base class "object" defined the type as "Callable[[object], int]") on __hash__
• I am in doubt on the identifier section. It should be an Optional[str], right?
• I have used the annotations.CoordinateType to annotate the last four functions at the bottom of the file. Therefore I've used the same type for getters and setters for bcpIn and bpcOut. Should that be the same for getters and setters of the anchor too?

[roberto-arista]

cc @knutnergaard