Add a check for parent condition status in nested conditions

[drewbutlerbb4]

Which issue is resolved by this Pull Request:
Resolves #397

Description of your changes:
Add a when expression checking the parent condition's status for all conditions that have a parent condition. Also update the UI to check if a condition status is available.

Environment tested:

• Python Version (use python --version):
• Tekton Version (use tkn version):
• Kubernetes Version (use kubectl version):
• OS (e.g. from /etc/os-release):

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[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: drewbutlerbb4

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[Tomcli]

/lgtm
/hold for a night before merging

[Tomcli]

/unhold