feat(exporters)!: collapse base classes into one

[pichlermarc]

Which problem is this PR solving?

Short description of the changes

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

• Unit tests

Checklist:

• Followed the style guidelines of this project
• Unit tests have been added
• Documentation has been updated

[codecov]

Codecov Report

Attention: Patch coverage is 43.54839% with 70 lines in your changes missing coverage. Please review.

Project coverage is 93.68%. Comparing base (859c0ef) to head (abff0e1).

Files with missing lines	Patch %	Lines
...ges/otlp-exporter-base/src/otlp-export-delegate.ts	8.82%	31 Missing ⚠️
...ges/otlp-exporter-base/src/export-promise-queue.ts	6.25%	15 Missing ⚠️
.../configuration/convert-legacy-node-http-options.ts	26.66%	11 Missing ⚠️
...ackages/otlp-exporter-base/src/OTLPExporterBase.ts	16.66%	5 Missing ⚠️
...er-metrics-otlp-http/src/OTLPMetricExporterBase.ts	66.66%	2 Missing ⚠️
...tlp-exporter-base/src/otlp-http-export-delegate.ts	71.42%	2 Missing ⚠️
...-exporter-base/src/otlp-network-export-delegate.ts	60.00%	2 Missing ⚠️
...-grpc-exporter-base/src/grpc-exporter-transport.ts	33.33%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5031      +/-   ##
==========================================
+ Coverage   93.26%   93.68%   +0.41%     
==========================================
  Files         317      317              
  Lines        8194     8072     -122     
  Branches     1640     1617      -23     
==========================================
- Hits         7642     7562      -80     
+ Misses        552      510      -42     

Files with missing lines	Coverage Δ
...ges/exporter-logs-otlp-grpc/src/OTLPLogExporter.ts	100.00% <100.00%> (ø)
...ogs-otlp-http/src/platform/node/OTLPLogExporter.ts	100.00% <100.00%> (ø)
...gs-otlp-proto/src/platform/node/OTLPLogExporter.ts	100.00% <100.00%> (ø)
.../exporter-trace-otlp-grpc/src/OTLPTraceExporter.ts	100.00% <100.00%> (ø)
...e-otlp-http/src/platform/node/OTLPTraceExporter.ts	100.00% <100.00%> (ø)
...-otlp-proto/src/platform/node/OTLPTraceExporter.ts	100.00% <100.00%> (ø)
...porter-metrics-otlp-grpc/src/OTLPMetricExporter.ts	100.00% <100.00%> (ø)
...-otlp-http/src/platform/node/OTLPMetricExporter.ts	100.00% <100.00%> (ø)
...orter-metrics-otlp-proto/src/OTLPMetricExporter.ts	100.00% <100.00%> (ø)
...ase/src/configuration/legacy-node-configuration.ts	100.00% <ø> (ø)
... and 14 more

... and 3 files with indirect coverage changes