feat: add plugin config options

[mayurkale22]

Which problem is this PR solving?

• Resolves Proposal: Plugin configuration options #214

Short description of the changes

• This is based on OPTION 1 mentioned in the Proposal: Plugin configuration options #214.

• Per SIG, OPTION 1 is more superior because it allows individual config.

• Note (per this implementation): only the individual config will get passed to the respective plugin.

[mayurkale22]

/cc @OlivierAlbertini Please review.

[codecov-io]

Codecov Report

Merging #229 into master will decrease coverage by 0.02%.
The diff coverage is 95.34%.

@@            Coverage Diff             @@
##           master     #229      +/-   ##
==========================================
- Coverage   98.94%   98.91%   -0.03%     
==========================================
  Files          67       67              
  Lines        2645     2495     -150     
  Branches      173      155      -18     
==========================================
- Hits         2617     2468     -149     
+ Misses         28       27       -1

Impacted Files	Coverage Δ
...metry-core/src/trace/instrumentation/BasePlugin.ts	11.11% <0%> (-1.39%)	⬇️
...ry-node-tracer/src/instrumentation/PluginLoader.ts	92.3% <100%> (+2.3%)	⬆️
...e-tracer/test/instrumentation/PluginLoader.test.ts	100% <100%> (ø)	⬆️
...telemetry-core/src/context/propagation/B3Format.ts	94.59% <0%> (-3.24%)	⬇️
...core/src/context/propagation/BinaryTraceContext.ts	96.15% <0%> (-2.21%)	⬇️
...s/opentelemetry-core/test/context/B3Format.test.ts	100% <0%> (ø)	⬆️
.../opentelemetry-exporter-jaeger/test/jaeger.test.ts	100% <0%> (ø)	⬆️
...s/opentelemetry-core/test/trace/tracestate.test.ts	100% <0%> (ø)	⬆️
...entelemetry-core/test/common/ConsoleLogger.test.ts	100% <0%> (ø)	⬆️
...entelemetry-exporter-jaeger/test/transform.test.ts	100% <0%> (ø)	⬆️
... and 16 more

[OlivierAlbertini]

LGTM. Could close #210 as well