[#30083] Add processing time to prism.

[lostluck]

Add a ProcessingTime queue to Prism's element manager, that can be appropriately controlled by the TestStream notion of time.

Basic design is that the queue doesn't contain the elements, but instead manages which stage needs to be notified when to inject queue elements into processing, and in particular, syncing it with existing watermark processing, which decides when elements are ready to be processed anyway. This allows continuing to have each stage maintain all the state for the stage, instead of splitting it between the element manager and the stages.

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[codecov[bot]]

Codecov Report

Attention: Patch coverage is 82.55814% with 15 lines in your changes are missing coverage. Please review.

Project coverage is 38.55%. Comparing base (6406cfe) to head (275e307). Report is 197 commits behind head on master.

:exclamation: Current head 275e307 differs from pull request most recent head 313bc5b. Consider uploading reports for the commit 313bc5b to get more accurate results

Files	Patch %	Lines
...am/runners/prism/internal/engine/elementmanager.go	26.66%	10 Missing and 1 partial :warning:
sdks/go/pkg/beam/runners/prism/internal/stage.go	85.18%	2 Missing and 2 partials :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #30492      +/-   ##
==========================================
+ Coverage   38.52%   38.55%   +0.02%     
==========================================
  Files         698      699       +1     
  Lines      102374   102439      +65     
==========================================
+ Hits        39442    39497      +55     
- Misses      61302    61307       +5     
- Partials     1630     1635       +5     

Flag	Coverage Δ
go	54.37% <82.55%> (+0.05%)	:arrow_up:

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[codecov-commenter]

Codecov Report

Attention: Patch coverage is 82.55814% with 15 lines in your changes are missing coverage. Please review.

Project coverage is 38.55%. Comparing base (b34cf54) to head (275e307). Report is 304 commits behind head on master.

:exclamation: Current head 275e307 differs from pull request most recent head 30c239d

Please upload reports for the commit 30c239d to get more accurate results.

Files	Patch %	Lines
...am/runners/prism/internal/engine/elementmanager.go	26.66%	10 Missing and 1 partial :warning:
sdks/go/pkg/beam/runners/prism/internal/stage.go	85.18%	2 Missing and 2 partials :warning:

Additional details and impacted files

@@              Coverage Diff              @@
##             master   #30492       +/-   ##
=============================================
- Coverage     71.44%   38.55%   -32.90%     
=============================================
  Files           906      699      -207     
  Lines        113271   102439    -10832     
  Branches       1076        0     -1076     
=============================================
- Hits          80931    39497    -41434     
- Misses        30327    61307    +30980     
+ Partials       2013     1635      -378     

Flag	Coverage Δ
go	54.37% <82.55%> (+0.04%)	:arrow_up:
java	?

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[lostluck]

R: @damondouglas

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

[lostluck]

LGTM pending the latest check re-run passes; nothing really stood out for me accept for the couple of comments.

The only failure was the Dataflow run of the ProcessingTime_Bounded test, which I had not filtered out. Dataflow only properly handles processing time in Streaming pipelines,and that test pipeline executes as "batch".