Allow to incrementally adopt new ID format in distributed system

[tobias-tengler]

In order to adopt the new ID format in a distributed system, you need to

1. Update services to support old and new format
2. Once all services support both formats, update services to start outputting the new ID format
3. Once all services are consuming and outputting the new ID format, get rid of the old format

Currently this adoption strategy wouldn't be possible, because while the new Default Serializer supports parsing both formats, it only outputs the new format, making it impossible to only update one service. The Legacy serializer only handles the old format, so it also can't be used to start adopting the new format.

This PR introduces a new option outputNewIdFormat for AddDefaultNodeIdSerializer. This allows you in the first step to update all your services to AddDefaultNodeIdSerializer(outputNewIdFormat: false) and once all services are updated, switch to outputting the new ID format via AddDefaultNodeIdSerializer().

[codecov]

Codecov Report

Attention: Patch coverage is 77.77778% with 4 lines in your changes missing coverage. Please review.

Project coverage is 76.61%. Comparing base (dfbe2fe) to head (1bc5893).

Files	Patch %	Lines
...s/Relay/Serialization/OptimizedNodeIdSerializer.cs	70.00%	3 Missing ⚠️
...n/RequestExecutorBuilderExtensions.IdSerializer.cs	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7343      +/-   ##
==========================================
- Coverage   77.06%   76.61%   -0.45%     
==========================================
  Files        2460     2786     +326     
  Lines      122123   139089   +16966     
==========================================
+ Hits        94108   106559   +12451     
- Misses      28015    32530    +4515     

Flag	Coverage Δ
unittests	76.61% <77.77%> (-0.45%)	⬇️

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