enh(test): improve operator== tests for DataObjects
Description
Some tests were written for DataObjects' operator==, but they aren't sufficient and must be improved.
Classes whose equality tests must be added/improved: Activity, BufferTL?, Camera, Color, DicomSeries, FrameTL, GenericField?, GenericTL?, Image?, ImageSeries, Landmarks, Line, MarkerMap?, Material, Matrix4, Mesh?, ModelSeries, Object?, Plane, PlaneList?, Point, PointList?, Reconstruction, Resection, ResectionDB?, Series, StructureTraits, StructureTraitsDictionary?, TimeLine?, TransferFunction?.
Functional specifications
The equality tests for the DataObjects are improved.
Technical specifications
The attributes of the DataObjects will be tested using the available setters and getters. When the objects must be equal, the equality is tested as well as the inequality. The unit tests for Series will be taken as an example.
Test plan
Run the new unit tests.