Verification of topology rules

@lbartoletti @Djedouas Finished integrating the student code on topology checking.

Add a section on topology rules in the interface

Topology rules checked:

• Validity of the geometry
• Duplicates
• Overlaps

Documentation and unit tests have been updated. Manual tests have been done with the 3 data formats, I have attached a test data set. test_data.zip

I added Humbert Fiorino and Jeremy Rousseau (owner of the shared code) as co-authors in the last commit.

Some areas of improvement:

• Improvement of the has_topology_errors function: I didn't try to optimize the code regarding checking for duplicates and overlaps. I just merged the check into one function. I wanted to use the Topology Checker tool but it is apparently not possible in PyQGIS.
• Adding the other topology rules of the Topology Checker tool.
• The duplicates and the overlaps are listed twice (e.g. Feature 1 is identical to the Feature 2, Feature 2 is identical to the Feature 1)
• Output format of the reports in json and html formats (the list of duplicates and overlaps must be interpreted differently than in a markdown report, e.g. replace the - with <br> in html).