Diffing_Engine: add PropertiesToInclude diffing workflow

[Stepsan]

Description:

Please could you include a function similar to the PropertiesToIgnore option, with which specific properties can be selected for comparison? An example of workflow:

• I have two lists of objects, of e.g. CustomObjects. The objects come from an external source, over which I have no control (e.g. a Revit model modified by an architect). However I know that each and every one of those objects will always have some known property assigned to them. For example, I know that all CustomObjects will have some property called propertyA and another called propertyB.
• I want to do the diffing between the lists of objects, based only on those known properties. For this, I would like to have an input called like propertiesToInclude where I can specify the name of the properties: propertyA and propertyB.
• The output can be in the form of a VennDiagram where the objects are dispatched to either "onlyInFirstList", "onlyInSecondList", or "both".

This can be useful for objects which include a lot of sub-properties that are either not known or liable to change.

[alelom]

Thanks @Stepsan ! 😄 🚀

[alelom]

@Stepsan I've edited the issue to elaborate a bit on what we said, hope you don't mind 😄
This shows the level of detail we need in Github issues to understand and work on them.
I'll start working on this ASAP 🚀