feat: allow for step status reporting to SCM as its own context

[ecrupper]

Ref: go-vela/community#576

Also fixes bug noted in go-vela/community#958 by setting the ground work to not report on the pull_request context when the action type is non-standard (opened, reopened, synchronize). Solving bugs with features!

This also lays some groundwork for potential usage of the checks API whenever Vela implements GitHub App integration

Server PR, in draft form, which may be more of interest: go-vela/server#1090

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.61%. Comparing base (a7d60df) to head (cda6f93).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #367      +/-   ##
==========================================
+ Coverage   96.60%   96.61%   +0.01%     
==========================================
  Files          69       69              
  Lines        5353     5375      +22     
==========================================
+ Hits         5171     5193      +22     
  Misses        109      109              
  Partials       73       73              

Files	Coverage Δ
database/step.go	100.00% <100.00%> (ø)
library/step.go	100.00% <100.00%> (ø)
pipeline/container.go	80.82% <100.00%> (+0.13%)	⬆️
yaml/step.go	95.45% <100.00%> (+0.10%)	⬆️

[wass3rw3rk]

do we need to account for people setting report_as to the same value? i can see that happen when folks use templates in particular maybe?

[ecrupper]

do we need to account for people setting report_as to the same value? i can see that happen when folks use templates in particular maybe?

Yeah I think that's a good point. Might be worth adding some validation in the compiler.

doubled up

[KellyMerrick]

lgtm