Modify health check extension to add new metrics health check functions

[skyduo]

Description:
This is a new health check method which allow customers to monitor the health status of containers based on the exporter functionally failures. It will return a 200/500 status when call the endpoint based on if the components can send data to the destination properly. Currently it only supports monitoring the exporter health status, will also support receivers and processors in the future.

Link to tracking Issue:
open-telemetry/opentelemetry-collector#2573

Testing:
make otelcontribcol and run executable file

Documentation:
https://docs.google.com/document/d/1SpUMsWA2DeaoVazeQ8uEc1Wvu5LphmQU_TjzLmuJ4QM/edit#heading=h.rs1luwizct2w

original pr was creating a new health check extension, but some community members think we should add the new feature in the existing one. Had discussion with @bogdandrutu and @Aneurysm9 and create this new pr.
previous pr:
#5144

[jpkrohling]

Tests started.

[Aneurysm9]

@skyduo please address this lint failure (and any others reported by running make golint locally):

healthcheckextension.go:75:7: shadow: declaration of "err" shadows declaration at line 48 (govet)
			if err := hc.server.Serve(ln); err != http.ErrServerClosed && err != nil {
			   ^

[skyduo]

not sure why make golint not work on my workspace even after i make install-tools and download the golint, but just resolve this issue it indicate

[skyduo]

hi @bogdandrutu ! could you help check and approve this pr if possible? Anthony and Juraci has approved, just wait for your final approval.

[skyduo]

Hey @bogdandrutu, since this pr is ready to merge, could you help approve it? Thanks!

[alolita]

Hi @bogdandrutu gentle reminder for a final review and merge from you for this PR. We would like to be able to make this feature available for OTEL users in the next release. Ty in advance!

[skyduo]

hi @bogdandrutu! i just resolve all the issues and merge it to a single commit, could you help approve it now?

[jpkrohling]

Could you please fix the merge conflict?

[skyduo]

hi @bogdandrutu! i just rebase and resolve the conflict, all tests pass now, could you help approve and merge it today? Thanks!