Add initially selected/visible threads and ordering setting

[parttimenerd]

The default selection of initially visible and selected threads is highly specific to the web use case, but rarely usable for imported profiles. The same is for the ordering, as the writer of the imported profile should have control over this too. This PR therefore introduces three new settings in the meta section of the profile format:

  // Indexes of the threads that are initially visible in the UI.
  // This is useful for imported profiles for which the internal visibility score
  // ranking does not make sense.
  initialVisibleThreads?: ThreadIndex[],
  // Indexes of the threads that are initially selected in the UI.
  // This is also most useful for imported profiles where just using the first thread
  // of each process might not make sense.
  initialSelectedThreads?: ThreadIndex[],
  // Keep the defined thread order
  disableThreadOrdering?: boolean,

This simple PR also includes tests (most of the lines of code) to check for the default and the new behavior.

Deployment preview production

[codecov[bot]]

Codecov Report

Base: 88.44% // Head: 88.45% // Increases project coverage by +0.00% :tada:

Coverage data is based on head (1f942b1) compared to base (7b3a30c). Patch coverage: 100.00% of modified lines in pull request are covered.

:exclamation: Current head 1f942b1 differs from pull request most recent head 84459ef. Consider uploading reports for the commit 84459ef to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4263   +/-   ##
=======================================
  Coverage   88.44%   88.45%           
=======================================
  Files         282      282           
  Lines       24857    24870   +13     
  Branches     6660     6666    +6     
=======================================
+ Hits        21985    21998   +13     
  Misses       2667     2667           
  Partials      205      205           

Impacted Files	Coverage Δ
src/profile-logic/tracks.js	83.85% <100.00%> (+0.39%)	:arrow_up:

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[julienw]

Have you tried specifying these directly in the URL?

[parttimenerd]

No, I thought that a converter should not rely on the URL to preselect threads.

[parttimenerd]

Any thoughts @julienw ?

[parttimenerd]

I resolved the small issues you mentioned. The whole idea of this PR is to allow the profile writer to specify that the order of thread tracks is the order of the threads in the profile file. This does not need a special field that specifies the order and is therefore the simplest solution for this problem (and the most obvious for the profile writer, as the current ordering is not really expected).

[parttimenerd]

I think the more complex option is better left for future discussions, especially as we would need to decide on which the current semantics really is. Is it really just startTime?

[parttimenerd]

I renamed the flag, so it should be ready?

[julienw]

I think the more complex option is better left for future discussions, especially as we would need to decide on which the current semantics really is. Is it really just startTime?

yeah I think startTime is the previous behavior and what some folks want. But I'm fine with keeping this to a future discussion.