[Feat]: Allow support for harness.io/pipelines annotations without the keys

[OrkoHunter]

🔖 Feature description

Currently the harness.io/pipelines annotations expects an array of key value pairs like this

metadata:
  annotations:
    harness.io/pipelines: |
      ci: ci_pipeline_link
      cd: cd_pipeline_link
      key1: url1

However it should also be possible to skip these keys here. If the keys are missing, then the pipeline name can be used as the keys in the dropdown list.

metadata:
  annotations:
    harness.io/pipelines: |
      ci_pipeline_link
      cd_pipeline_link
      url1

or simply

metadata:
  annotations:
    harness.io/pipelines: pipeline_link

🎤 Context

✌️ Possible Implementation

backstage-plugins/plugins/harness-ci-cd/src/components/ExecutionList/ExecutionList.tsx

Lines 291 to 296 in 32d285f

	{Object.keys(harnessPipelineObject).length > 0 ? (
	<ListSubheader>Pipelines</ListSubheader>
	) : null}
	{Object.keys(harnessPipelineObject).map(envId => (
	<MenuItem value={harnessPipelineObject[envId]}>{envId}</MenuItem>
	))}

[OrkoHunter]

Context from Internal Slack: https://harness.slack.com/archives/C066C0AH4DU/p1721065085930089?thread_ts=1721059219.517469&cid=C066C0AH4DU

[OrkoHunter]

cc @Debanitrkl @jenil-harness @sandeepa-kv-jois