Better handling of large designs

[tomcl]

Is your feature request related to a problem? Please describe.

Issie designs with large numbers of simulated components are laggy, even when editing

Describe the solution you'd like

I'd like editing to be unaffected by the (long) simulation time caused by excessive simulation heap use. I'd like laggy simulations to be detected and:

• Simulation array size decreased as needed to make simulation time ok
• Simulations that remain too large should result in a popup when simulating - not an out-of-memory crash
• Simulations that are too large should not happen when editing a design (currently they do as part of design validation).

Additional context A simple design leading to a very large simulation that crashes Issie:

largeTest.zip

[tomcl]

See also https://github.com/tomcl/issie/discussions/534