fix: isolate binding EventEmitter

[Flarna]

Which problem is this PR solving?

Binding an EventEmitter a second time via another instances of ContextManager shouldn't have side effects to the first ContextManager.

Short description of the changes

Use an unique symbol per ContextManager instance to isolate them.

[codecov]

Codecov Report

Merging #1937 (8c80ee1) into main (38d1ee2) will increase coverage by 0.12%.
The diff coverage is 96.55%.

@@            Coverage Diff             @@
##             main    #1937      +/-   ##
==========================================
+ Coverage   92.76%   92.88%   +0.12%     
==========================================
  Files         174      174              
  Lines        6108     6061      -47     
  Branches     1265     1250      -15     
==========================================
- Hits         5666     5630      -36     
+ Misses        442      431      -11     

Impacted Files	Coverage Δ
...sync-hooks/src/AbstractAsyncHooksContextManager.ts	96.87% <96.42%> (-1.24%)	⬇️
...async-hooks/src/AsyncLocalStorageContextManager.ts	100.00% <100.00%> (ø)
...emetry-core/src/platform/node/RandomIdGenerator.ts	87.50% <0.00%> (-6.25%)	⬇️
...etry-exporter-prometheus/src/PrometheusExporter.ts	90.66% <0.00%> (-1.34%)	⬇️
...ages/opentelemetry-exporter-collector/src/types.ts
...ry-exporter-collector/src/CollectorExporterBase.ts
.../opentelemetry-exporter-collector/src/transform.ts
...lemetry-exporter-collector/src/transformMetrics.ts
...kages/opentelemetry-exporter-collector/src/util.ts
...ntelemetry-web/src/enums/PerformanceTimingNames.ts	100.00% <0.00%> (ø)
... and 5 more

[obecny]

some minor things

[obecny]

approving, the last thing is minor anyway leaving this up to you