Changing causal-loop to causal-loop-delays breaks ODE analysis

[kasbah]

My backwards compat test (#1075) caught this on production. An anonymous user:

1. Created a causal-loop model
2. Created a linear-ode analysis
3. Switched causal-loop to causal-loop-delays

This now gives an error since linear-ode doesn't exist on causal-loop-delays: https://catcolab.org/analysis/019eb774-8012-737e-a7fb-db0eb1cc38f7

[tim-at-topos]

Just to document some thoughts that we discussed in person, note that there are a few options for how to deal with this (not all mutually exclusive or contradictory, but some)

1. Fix Error in individual analysis breaks an entire analysis document #1076 so that an individual broken analysis doesn't break the entire document
2. Only allow migration to theories that support at least the same analyses
3. Give a warning when migrating to a theory that doesn't support an analysis in any analysis notebook of the model notebook
4. Give a checkbox to ask whether analysis notebooks should also be migrated alongside the model notebook when migrating

[epatters]

Thanks for filing this report. I've known this was a latent bug, but given that

• our support for model migrations is generally provisional and half-baked, and
• analyses are under-theorized and thus how they should transform under migration is not very clear,

I've been reluctant to spend much effort on a principled fix.

That said, of @tim-at-topos's suggestions, I like (1) because it will generally increase the stability/recoverability of the app and will become essential once analyses can be contributed by users via a plugin system. As a bonus, it will work around conceptual problems like this one until we're ready to prioritize improving migrations.