Change the API to create events to be versioned

[afrittoli]

Do a few changes in preparation for support of multiple versions:

• relocate the spec submodule to be versioned (by spec version)
• add the even version in event types

This has an impact on the API, so what used to be:

event, _ := cdevents.NewPipelineRunQueuedEvent()

Will become instead:

event, _ := cdevents.NewPipelineRunQueuedEventV0_1_1()

The parsing and rendering APIs do not change.
Upcoming PRs will add objects to identify the collection of event versions that belong to a specific spec version, to let users select the spec version rather than having to pick individual event versions.

[codecov]

Codecov Report

Attention: Patch coverage is 87.37327% with 137 lines in your changes are missing coverage. Please review.

❗ No coverage uploaded for pull request base (main@df9a2db). Click here to learn what that means.

Files	Patch %	Lines
tools/generator.go	7.14%	13 Missing ⚠️
pkg/api/zz_testcaserunfinished_0_1_0.go	79.31%	6 Missing ⚠️
pkg/api/zz_testcaserunqueued_0_1_0.go	85.18%	4 Missing ⚠️
pkg/api/zz_testcaserunstarted_0_1_0.go	85.18%	4 Missing ⚠️
pkg/api/zz_testoutputpublished_0_1_0.go	85.18%	4 Missing ⚠️
pkg/api/zz_artifactpackaged_0_1_1.go	87.50%	3 Missing ⚠️
pkg/api/zz_artifactpublished_0_1_1.go	86.95%	3 Missing ⚠️
pkg/api/zz_artifactsigned_0_1_0.go	87.50%	3 Missing ⚠️
pkg/api/zz_branchcreated_0_1_2.go	87.50%	3 Missing ⚠️
pkg/api/zz_branchdeleted_0_1_2.go	87.50%	3 Missing ⚠️
... and 31 more

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #77   +/-   ##
=======================================
  Coverage        ?   80.05%           
=======================================
  Files           ?       46           
  Lines           ?     3164           
  Branches        ?        0           
=======================================
  Hits            ?     2533           
  Misses          ?      524           
  Partials        ?      107           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.