Decompose conflated user-facing PipelineRunStatus/ TaskRunStatus failure reasons

[JeromeJu]

Current behaviour:

There exist PipelineRun and TaskRun failure reasons are conflated with others that are non-related with the description of the PipelineRun and TaskRun reason. For example, as for PipelineRunReasonFailedValidaion which should indicate that the Pipelinerun runtime validation failure mixes up the failure reasons of InvalidPipelineResult and InvalidParamsResolvedPipelineTasks. Similarly for TaskRunFailedValidation conflating InvalidParamArrayIndex and etc. which should have been using clearer failure reasons.

Expected behaviour:

• Examine the granularity PipelineRunReason/TaskRunReason used in failures in the pipeline reconciler.
  • Ideally, similar to exit codes, each PipelineRunReason and TaskRunReason should be unique and clearly identify the specific failure cause, preventing confusion with other reasons.
• Break down the conflated failure PipelineRun/TaskRun Reasons according to the root failure causes.

/kind cleanup

[JeromeJu]

Closing as covered in #7501 and continued at TEP0151-Error attribution via Condition Status