api: Add scheduledAt field to tasks to allow proper time-to-ready metric

[victorges]

What does this pull request do? Explain your changes. (required)
This adds a scheduledAt field to tasks so we can tell how long an asset
actually took to upload then how long it actually took to be processed.

upload time = task->scheduledAt - task->createdAt
time to ready = task->status->updatedAt - task->scheduledAt

On the way, also added an uploading phase to assets cause we need that for too long already.

Specific updates (required)

• Add scheduledAt field to tasks and udpate them from scheduler
• Add uploading phase to assets and update it from controller
• Rename scheduler task scheduling functions

How did you test each of these updates (required)
in yarn tests we trust

Does this pull request close any open issues?
Implements API-31

Checklist

• I have read the CONTRIBUTING document.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.

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Name	Status	Preview	Comments	Updated
livepeer-studio	✅ Ready (Inspect)	Visit Preview	💬 Add your feedback	Mar 22, 2023 at 8:20PM (UTC)

[gioelecerati]

LGTM!

[codecov]

Codecov Report

Merging #1667 (f2c9cb2) into master (9bf4d71) will increase coverage by 0.03705%.
The diff coverage is 65.38462%.

@@                 Coverage Diff                 @@
##              master       #1667         +/-   ##
===================================================
+ Coverage   53.13268%   53.16973%   +0.03705%     
===================================================
  Files             74          74                 
  Lines           4884        4890          +6     
  Branches         941         944          +3     
===================================================
+ Hits            2595        2600          +5     
  Misses          1961        1961                 
- Partials         328         329          +1     

Impacted Files	Coverage Δ
packages/api/src/webhooks/cannon.ts	46.28571% <0.00000%> (ø)
packages/api/src/controllers/asset.ts	58.80682% <64.70588%> (+0.47349%)	⬆️
packages/api/src/task/scheduler.ts	50.00000% <71.42857%> (ø)
packages/api/src/controllers/transcode.ts	91.66667% <100.00000%> (ø)

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Impacted Files	Coverage Δ
packages/api/src/webhooks/cannon.ts	46.28571% <0.00000%> (ø)
packages/api/src/controllers/asset.ts	58.80682% <64.70588%> (+0.47349%)	⬆️
packages/api/src/task/scheduler.ts	50.00000% <71.42857%> (ø)
packages/api/src/controllers/transcode.ts	91.66667% <100.00000%> (ø)