Split the web and metrics service endpoints

[jonathanio]

Refactor the application service configuration to split the web and metrics endpoints onto their own ports and update the Helm configuration to facilitate this.

This should allow the health and monitoring URIs to be served off a dedicated metrics port, accessible from any public location, and allow the cluster to privately access information about the service while the main web endpoint serves all normal functions through the Ingress
configurations.

Checklist

Before raising or requesting a review of the pull request, please check and confirm the following items have been performed, where possible:

• I have performed a self-review of my code and run any tests locally to check
• I have added tests that prove that any changes are effective and work correctly
• I have made corresponding changes, as needed, to the repository documentation
• Each commit in, and this pull request, have meaningful subjects and bodies for context
• I have added release/..., type/..., and changes/... labels, as needed, to this pull request

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 297 lines in your changes missing coverage. Please review.

Project coverage is 10.16%. Comparing base (ab67c09) to head (f9da282).

Files	Patch %	Lines
internal/serve/metrics/main.go	0.00%	72 Missing ⚠️
internal/serve/web/main.go	0.00%	67 Missing ⚠️
internal/cmd/serve.go	0.00%	58 Missing ⚠️
internal/serve/middleware/metrics.go	0.00%	54 Missing ⚠️
internal/serve/metrics/healthz/main.go	0.00%	16 Missing ⚠️
internal/serve/middleware/logger.go	0.00%	13 Missing ⚠️
internal/serve/middleware/prometheus.go	0.00%	11 Missing ⚠️
internal/serve/web/ping/main.go	0.00%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main       #7      +/-   ##
==========================================
- Coverage   14.79%   10.16%   -4.64%     
==========================================
  Files          13       17       +4     
  Lines         338      492     +154     
==========================================
  Hits           50       50              
- Misses        288      442     +154     

Flag	Coverage Δ
unit-tests	10.16% <0.00%> (-4.64%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
internal/serve/metrics/alive/main.go	0.00% <ø> (ø)
internal/serve/web/ping/main.go	0.00% <0.00%> (ø)
internal/serve/middleware/prometheus.go	0.00% <0.00%> (ø)
internal/serve/middleware/logger.go	0.00% <0.00%> (ø)
internal/serve/metrics/healthz/main.go	0.00% <0.00%> (ø)
internal/serve/middleware/metrics.go	0.00% <0.00%> (ø)
internal/cmd/serve.go	0.00% <0.00%> (ø)
internal/serve/web/main.go	0.00% <0.00%> (ø)
internal/serve/metrics/main.go	0.00% <0.00%> (ø)