enhance(yaml)!: allow for users to parse pipelines using old library

[ecrupper]

Background

It is imperative that the platform moves away from the buildkite YAML library, as it is archived.

This has been attempted and reverted a couple times:

(2024, go-yaml v3) go-vela/types#386 —> go-vela/types#392

(2020, goccy) go-vela/types#118 —> go-vela/types#144

This PR ensures that we will not have to revert this important change, as it will allow for users to immediately set

version: "legacy"

At the top level of their pipeline file (or template file) if they are encountering unexpected YAML issues.

This will also allow for troubleshooting / triaging for the Vela admins to cover all of our bases when shifting to this new library while having low impact.

The goal is to revert this change in a later release so that the entire platform uses only one YAML parser throughout the code base.

However, one of the most common patterns that will now produce errors is the use of multiple <<: in a single YAML map. This pattern will compile correctly with this change but produce warnings. These warnings will be attached to the pipeline object and will be rendered in the UI.

What's in the PR

• new packages compiler/types/yaml/yaml and compiler/types/yaml/buildkite in place of the single compiler/types/yaml
• all the buildkite YAML types have a ToYAML() method that will convert to the go-yaml version. Once the pipelines have been unmarshaled, these two objects should be identical sans their type.
• an internal/yaml.go file that grabs the version from the pipeline file and verifies the library we should use.
• a new warnings field in the pipelines table to track warnings.

[codecov]

Codecov Report

Attention: Patch coverage is 73.10726% with 341 lines in your changes missing coverage. Please review.

Project coverage is 57.50%. Comparing base (aa973fe) to head (ef30880).

Files with missing lines	Patch %	Lines
compiler/types/yaml/buildkite/secret.go	72.72%	49 Missing and 2 partials ⚠️
compiler/types/yaml/buildkite/template.go	43.75%	36 Missing ⚠️
compiler/types/yaml/buildkite/step.go	65.68%	34 Missing and 1 partial ⚠️
compiler/types/yaml/buildkite/service.go	65.90%	28 Missing and 2 partials ⚠️
compiler/types/yaml/buildkite/ruleset.go	81.81%	28 Missing ⚠️
compiler/template/starlark/render.go	38.46%	24 Missing ⚠️
compiler/types/yaml/buildkite/stage.go	19.23%	21 Missing ⚠️
compiler/types/yaml/buildkite/metadata.go	66.10%	20 Missing ⚠️
internal/yaml.go	81.48%	15 Missing and 5 partials ⚠️
compiler/types/yaml/buildkite/ulimit.go	80.61%	19 Missing ⚠️
... and 9 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1220      +/-   ##
==========================================
+ Coverage   56.91%   57.50%   +0.58%     
==========================================
  Files         599      611      +12     
  Lines       32904    34085    +1181     
==========================================
+ Hits        18727    19600     +873     
- Misses      13541    13835     +294     
- Partials      636      650      +14     

Files with missing lines	Coverage Δ
api/types/pipeline.go	100.00% <100.00%> (ø)
api/types/string.go	80.64% <ø> (ø)
compiler/native/clone.go	100.00% <ø> (ø)
compiler/native/compile.go	71.29% <100.00%> (+0.13%)	⬆️
compiler/native/environment.go	86.75% <ø> (ø)
compiler/native/initialize.go	100.00% <ø> (ø)
compiler/native/script.go	95.23% <ø> (ø)
compiler/native/substitute.go	70.00% <ø> (ø)
compiler/native/transform.go	95.34% <ø> (ø)
compiler/native/validate.go	96.93% <ø> (ø)
... and 33 more