Base_oM: make BaseComparisonConfig IImmutable

[alelom]

Description:

This would be a good idea in general, in order to ensure that no external modification happens after an instance of ComparisonConfig is given to diffing/hash.

Additionally, if we introduce #1587 , the properties stop being fully orthogonal, as UseGeometryHash is not fully compatible with the other configurations (unless proven otherwise -- requires further investigation). In this case, Immutability becomes a requirement.

Introducing IImmutable in the BaseComparisonConfig requires the following:

1. Change all collections to ReadOnly collections. This is to avoid tampering with the collections themselves.
2. Normally, a ReadOnlyCollection would be enough, but it's better to introduce a ReadOnlyHashset for BaseComparisonConfig in order ensure optimisation when computing Hash/Diffing. This requires introducing this new class in the Base_oM. Example implementation here.
3. We need to align all repos to this change, introducing constructors. This includes Revit_Toolkit and DiffingTests_prototypes.

@pawelbaran FYI

[alelom]

We decided to go for this instead:

• Geometry_Engine: GeometryHash() to support the options from BaseComparisonConfig BHoM_Engine#3269
• Base_Engine: Hash to leverage the new aggregating GeometryHash method for geometry types BHoM_Engine#3255