[#28543][prism] Implement State API

[lostluck]

Adds State API handling to Prism.

In particular:

• Stateful stages are forced to be fusion roots.
• Persisted state is added to engine.stageState
• Tentative state is held onto in worker.Bundle, and mutated there as needed.
• Add eager key extracting parsing for stateful receiving stages.
  • Very inefficient at present.
• Implements FnAPI handling for:
  • BagState
  • MultimapState
  • MultimapKeysState
• Unified handling for the two main state kinds
  • WRT/ Garbage collection and copying to bundles, and interaction.
• Added a variable for State Unit Tests to switch between to stateful execution modes:
  • Greedily pack bundles with all data and state.
  • One Element Per Key.
  • One Key per Bundle.
  • One Element per Key, one key per Bundle.

Resolves #28543

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[github-actions]

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[codecov]

Codecov Report

Attention: 84 lines in your changes are missing coverage. Please review.

Comparison is base (dae646b) 37.85% compared to head (e1346e8) 38.15%.
Report is 140 commits behind head on master.

Files	Patch %	Lines
...o/pkg/beam/runners/prism/internal/worker/worker.go	10.16%	52 Missing and 1 partial ⚠️
...am/runners/prism/internal/engine/elementmanager.go	92.54%	9 Missing and 3 partials ⚠️
...m/runners/prism/internal/jobservices/management.go	0.00%	11 Missing and 1 partial ⚠️
.../go/pkg/beam/runners/prism/internal/engine/data.go	95.91%	3 Missing and 1 partial ⚠️
...s/go/pkg/beam/runners/prism/internal/preprocess.go	72.72%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #29712      +/-   ##
==========================================
+ Coverage   37.85%   38.15%   +0.30%     
==========================================
  Files         690      696       +6     
  Lines      101352   102086     +734     
==========================================
+ Hits        38363    38954     +591     
- Misses      61395    61514     +119     
- Partials     1594     1618      +24     

Flag	Coverage Δ
go	53.93% <78.06%> (+0.53%)	⬆️

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R: @riteshghorse for label go.

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[lostluck]

I thought I made this a draft PR. I still have a bit more cleanup / deduplication to do Ritesh. Sorry for the inconvenience.

[lostluck]

R: @riteshghorse

Ready for a look! Thanks for your patience. No rush to get the review in for 2.53.0, it's OK if it's not in the cut.

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Stopping reviewer notifications for this pull request: review requested by someone other than the bot, ceding control

[riteshghorse]

Mostly looks good, one question!

[riteshghorse]

LGTM, thanks!