Improve status messages for protected pipelines

[qwerty287]

Clear and concise description of the problem

Currently, the status sent back to the forge looks like this:

state	status	message
pipeline waits for approval	pending	Pipeline is pending
pipeline is declined	pending	Pipeline is pending

Suggested solution

It should look like:

state	status	message
pipeline waits for approval	pending	Pipeline waits for approval
pipeline is declined	failed	Pipeline was declined

Alternative

No response

Additional context

No response

Validations

• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.