Add Heuristic Backbone

[robertjosephpalermo]

@fxcosta-phd

• Adds the heuristic backbone function
• Cleans up the code that was already there

[fxcosta-phd]

@robertjosephpalermo It would be best to clean up the code prior to merging. Here is my brief revision:

• It seems that most of the changes was separating the function arguments to multiple lines instead of a single line. Please keep them all in a single line.
• Why line 155 has disjuntion=drastic_disjunction?
• The code now seems to import Callable, why?
• There was a test_heuristic_backbone function in here which should still exist, but in a different file, namely in the test folder.

[robertjosephpalermo]

@robertjosephpalermo It would be best to clean up the code prior to merging. Here is my brief revision:

• It seems that most of the changes was separating the function arguments to multiple lines instead of a single line. Please keep them all in a single line.
• Why line 155 has disjuntion=drastic_disjunction?
• The code now seems to import Callable, why?
• There was a test_heuristic_backbone function in here which should still exist, but in a different file, namely in the test folder.

1. Yes many of the changes were reformatting the long function lines with the intention of increasing readability. I will change it back.
2. I will fix that, it should be just "disjunction".
3. "Callable" is used as a type hint for the disjunctions, for example in the "_local_semi_triangles" function.
4. I will add back the test file.