feat: add pg-pool to default list of instrumented plugins

[mayurkale22]

Which problem is this PR solving?

• add pg-pool to default list of instrumented plugins

/cc @xiao-lix

[codecov-io]

Codecov Report

Merging #662 into master will increase coverage by 0.06%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #662      +/-   ##
==========================================
+ Coverage   89.66%   89.72%   +0.06%     
==========================================
  Files         213      213              
  Lines       10043    10068      +25     
  Branches      935      936       +1     
==========================================
+ Hits         9005     9034      +29     
+ Misses       1038     1034       -4

Impacted Files	Coverage Δ
...opentelemetry-base/test/resources/resource.test.ts	100% <0%> (ø)	⬆️
...ges/opentelemetry-exporter-zipkin/src/transform.ts	100% <0%> (ø)	⬆️
.../opentelemetry-exporter-zipkin/test/zipkin.test.ts	100% <0%> (ø)	⬆️
packages/opentelemetry-web/src/WebTracer.ts	100% <0%> (ø)	⬆️
...try-node/test/instrumentation/PluginLoader.test.ts	100% <0%> (ø)	⬆️
packages/opentelemetry-plugin-https/src/utils.ts	100% <0%> (ø)	⬆️
...telemetry-scope-base/test/NoopScopeManager.test.ts	100% <0%> (ø)	⬆️
...entelemetry-exporter-zipkin/test/transform.test.ts	100% <0%> (ø)	⬆️
...ackages/opentelemetry-exporter-zipkin/src/utils.ts	100% <0%> (ø)
...es/opentelemetry-node/src/instrumentation/utils.ts	100% <0%> (+9.52%)	⬆️
... and 1 more