Totally omit a class' mermaid diagram if there are more than n slots

[turbomam]

Possible N = 60 (or whatever fits vertically on one average screen)

In the future, we might think about ways to show the structural part of the mermaid diagram without the slots, but just omitting diagrams with excessive slots is a good start.

[turbomam]

see also

• show middle layer elements in inheritance tree in mermaid #441

[turbomam]

see also

• remove mermaid diagrams until they are more useful #440

[turbomam]

see also:

• Class: biosample diagram URL produces 414 URI Too Long error NMDC_documentation#10

[sujaypatil96]

In this issue we're saying that we should use one parameter, the total number of slots associated with a class to decide whether the Mermaid UML diagram should be rendered on a class documentation page or not.

I'm proposing that we add three more parameters to make this decision. They are:

• Number of edges between given class (in consideration) and is_a parents
• Number of edges between given class (in consideration) and is_a children
• Number of edges between given class (in consideration) and other classes that are linked/associated based on a slot

[sujaypatil96]

The above has been implemented in PR #1625 in class_diagram.md.jinja2