Fix infinite reload of sample lists

[alisman]

When a user views a virtual study without any mutations, the result view page will fire an infinite number of backend requests to /api/session/virtual_study.
This is caused by an infinite loop in the QueryStore that keeps recalculating sampleLists when selecting a virtual study.

(This PR also adds some documentation on the localdev property that is needed to debug the frontend using https.)

Reproduce bug

The bug can be reproduced by:

• importing a study without mutations;
• using cbioportal with https
• selecting the virtual study on the index page by clicking the checkbox next to it (not the 'pie chart' link to the study);
• click 'explore selected studies' on the index page

Fix

The onResult handlers were mutating state on which the invoke dependend, causing infinite loop. This gets rid of the onResult and moves the clearing of the sample list selection state to the study selection handler. Whenever studies are selected/deselected, the sample list is reset to default.

[alisman]

@BasLee this is the offending onResult. It depends upon this._selectedSampleListId, so when it mutates that value it re-fires invoke and is circular.

[alisman]

I believe that it was necessary in order to clear the selection when user selected a different study. This can/should be handled on read by checking to see if the _selectedSampleListId matches selectedStudies

[BasLee]

the weird thing was, that the infinite loop even existed without any code in the onResult: it seemed like the presence of onResult itself was causing the loop

[alisman]

interesting. i will test that.

[alisman]

i see that you are right. in my testing, the problem is that mobxpromise's onResult references this.result in order to pass it to the callback:

when i use result instead of this.result, the problem goes away. will have to make this change to the library.

nevertheless, i think getting rid of onResult in general is a good idea as it is almost never actually necessary.

[BasLee]

this is an unrelated improvement/bug fix?

[alisman]

yeah, download mode doesn't exist anymore so I've been trying to clean this stuff out, but i should probably do it in a seperate PR

[alisman]

@BasLee thanks to your detective work, we have found that there is a problem in mobxpromise library itself. However, that doesn't change the fact that the use of onResult in this case (and probably almost all other cases) is misguided. In general, it's subject to observability problems. I.e. I think that my refactor makes sense to merge and we can follow up later with the change to library.