[prism] Universal runner improvements.

[lostluck]

Improve the universal runner in two key ways to unblock prism adoption.

• For loopback mode execution, avoid unecessary compile and upload costs when the binary isn't overridded. Uses an empty temporary file. Filed [Task][Go SDK]: Determine canonical local temp directory.  #27569 to have a better canon location for this.
• Cache the most recent error log from the message stream and report that as the cause of job failure, vs the previous error reporting which was merely "job failed". For runners that actually report job failure messages, this can reduce time for debugging and iteration.

Prism will make use of these, but any portable runner or loopback runner can make use of them. In particular, the message holding replicates what the direct runner can do with failues during its single threaded execution. There are unit tests in the SDK that rely on this behaviour, but it is extremely useful too.

See #27550 and #24789.

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[codecov]

Codecov Report

Merging #27570 (36bb905) into master (b2e00ef) will decrease coverage by 0.02%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master   #27570      +/-   ##
==========================================
- Coverage   71.14%   71.13%   -0.02%     
==========================================
  Files         861      861              
  Lines      104560   104582      +22     
==========================================
+ Hits        74389    74393       +4     
- Misses      28621    28640      +19     
+ Partials     1550     1549       -1     

Flag	Coverage Δ
go	53.63% <0.00%> (-0.03%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files Changed	Coverage Δ
...go/pkg/beam/runners/universal/runnerlib/execute.go	0.00% <0.00%> (ø)
...dks/go/pkg/beam/runners/universal/runnerlib/job.go	0.00% <0.00%> (ø)

... and 2 files with indirect coverage changes

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[riteshghorse]

LGTM! Nice improvement with loopback mode!