Bug fixed in isisminer to properly handle self-intersecting polygon geometries. (#5620)

* Fixed issues with GisGeometry/Strategy classes. Addresses #5612.

* GisGeometry was throwing an exception when isValid() was called and the geometry was indeed invalid
* GisGeometry - added buffer() method
* Strategy was updated to better manage geometries
* Strategy - Added RepairInvalidGeometry and InvalidGeometryAction to allow better user control over invalid geometries
* Strategy - Apply buffer(0) algorithm when an invalid geometry is detected
* Strategy - Added more debug output

* Corrected invalid geometry problems in isisminer. Addresses #5612.

* GisGeometry was throwing an exception when isValid() was called and the geometry was indeed invalid
* GisGeometry - added buffer() method
* Strategy was updated to better manage geometries
* Strategy - Added RepairInvalidGeometry and InvalidGeometryAction to allow better user control over invalid geometries
* Strategy - Apply buffer(0) algorithm when an invalid geometry is detected
* Strategy - Added more debug output
* isisminer - improved handling of invalid/bad geometries
* isisminer - Documented new parameters RepairInvalidGeometry and InvalidGeometryAction and updated Calculator strategy documentation

* Fixed a bug in isisminer in which bad (e.g. self-intersecting) polygon geometries were not treated properly. Added pertinent unit tests to GisGeometry and Strategy classes. Fixed incorrect links and minor typos in isisminer documentation. Addresses #5612.

* Per reviewer comments, corrected additional typos in GisGeometry.cpp. Addresses #5612.

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Co-authored-by: Kris J. Becker <kbecker@orex.lpl.arizona.edu>