Fix: show rate expression instead of rate name

[blanchco]

Description

• Show rate expression instead of rate name
• Did some post processing on the transition in the ACset before we send it to the acset-to-latex endpoint.
• expressions will show within brackets

Resolves #(issue)

[mwdchang]

So I noticed there is a slight discrepancy here, for example we have

• susceptible, versus
• susceptible(t)

Is this something we should address @liunelson

[liunelson]

I have a few comments:

1. Why are we still using an ACSet-to-LaTeX converter, as opposed to an AMR-to-LaTeX converter? It took me a little to even find a ACSet to even test that model-service endpoint!
2. (t) in the returned LaTeX should probably be always not shown since it is effectively redundant. The fact that an entity has a differential equation d X / d t = f(X) associated with it is sufficient to determine that it is time-dependent. Furthermore, I tested TA1's equation-to-AMR converter and found that it strips the (t) anyway. Showing the (t) would make the user type more LaTeX than necessary.
3. It is becoming increasingly untenable to permit parameters and variables to have IDs that are words (i.e. multi-character strings). Justin (developer for the TA1 equation-to-AMR converter) says that we should be only allowing IDs of the form X_{abc} (not Xabc, abc, X_abc, etc.). Else, we risk interconverting AMRs and equations that interpret a variable/parameter ID such as poParam into the product of p, o, P, a, r, a, m.
4. It is somewhat mentally taxing to read rendered equations and map them to un-rendered ones in the graph. Ideally, the equations in the graph should be rendered as well. Same goes with the labels of the state variables.
5. Generally, when typesetting math equations, multiplication is implicit - i.e. no *, maybe a non-breaking space. The asterisk or star symbol * is usually reserved for special operators like convolution or complex conjugation. If we really want to show multiplication, the standard is to use \cdot (i.e. ·) symbol.

[blanchco]

Updates:

• Now we can no longer edit equations when a model is already present as per the outcome of the discussion

Screen.Recording.2023-09-07.at.3.01.10.PM.mov