enhance(metrics)!: query parameter support on metrics endpoint

[plyr4]

what?

this adds query parameter support to the /metrics endpoint.

why?

without selective querying, the /metrics endpoint will perform expensive and exhaustive queries to retrieve information from the database

breaking change!

the default values for each query parameter are false so that you must selectively request additional information from the database, which means anyone using the /metrics endpoint as it works currently will stop receiving data unless they update their query from

curl 'localhost:8080/metrics'

to

curl 'localhost:8080/metrics?user_count=t&build_count=true'

and include each piece of data they would like to query for.

docs

once i get approval on the structure and usage of the parameters i will create the documentation before merging

[codecov]

Codecov Report

Merging #682 (0a89f9e) into master (048364c) will decrease coverage by 0.12%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master     #682      +/-   ##
==========================================
- Coverage   55.20%   55.07%   -0.13%     
==========================================
  Files         201      201              
  Lines       15916    15952      +36     
==========================================
  Hits         8786     8786              
- Misses       6752     6788      +36     
  Partials      378      378              

Impacted Files	Coverage Δ
api/metrics.go	0.00% <0.00%> (ø)

[cognifloyd]

I don't use the metrics endpoint so far, but this looks sane from reading.

[ecrupper]

LGTM