Make relations in the database more presentable

[itaybthl]

Though the ultimate end goal for LIReC is to have an interactive hypergraph that shows vertices as database values and hyperedges as relations, a much more realistic goal would be to employ PyLaTeX to format relations in more presentable math. Refer to devutils/print_relations_v2 for code that can get you started.
The exact details of the solution don't matter, so long as:

• Relations are rendered in a readable way, either by predefining $PCF[a_n,b_n]$ and then reusing that notation, or explicitly writing out a few iterations of each PCF and then including the explicit general term(s), such as in elimelech. Every relation that contains only one PCF should isolate for that PCF before printing each side of the formula.
• The code contains the (rudimentary) "explained by/related to" feature of the existing devutils/print_relations. Essentially, both print_relations and print_relations_v2 should be combined somehow.
• The code has options for filtering relations based on
  • which constants participate, and/or
  • max degree and/or max order., and/or
  • whether or not they are "transitive/explainable relations". (this filter will be on by default)

Again, this issue is a lot more amorphous than the others, so feel free to discuss ideas with us as they come up.