App is slow when loading a large workchain

[mikibonacci]

When opening a completed QeAppWorkChain which contains several sub-workchains and calcjobs, the app is critically slow. For example, for a muon run with 6 PwRelaxWorkChains and 30 WorkGraphs+Pythonjobs, it takes 2-3 mins. I guess it concerns particularly very nested WorkChains*:

QeAppW->ImplantMuonW->FindMuonW
| ->several PwRelaxW->several PwBaseW->several PwCalculation +
|
->WorkGraph->several WorkGraph->several Pythonjobs

(*I think this because the PhononWorkChain, even when a lot of calculations are done, is not so slowed down - on average - , as it calls just PwBaseWorkChains + three PhonopyCalculations.)

Pinging @edan-bainglass and @superstar54 to discuss this next week in person (I am willing to work on it, but let's first discuss)

[edan-bainglass]

@mikibonacci in the current state, surely the status tree would be slow. Is that what you're experiencing, or the whole app?

[mikibonacci]

@edan-bainglass I guess the tree, as the critical part is the population of step 4 (after that, it is fast as usual)

[edan-bainglass]

Okay yeah, the tree is not optimal. Need to rethink. Let's discuss.