Frontend: Lazy Load Manual Builds to avoid Request Timeouts

In #207994 (comment 615734394) @allison.browne proposed the following:

pipeline.details.manual_actions could be lazy loaded when the arrow is clicked to view the manual actions, which would also have the effect of only loading the actions for a single pipeline at a time rather than all of the manual jobs for all of the pipelines.

This issue tracks the frontend portion of this effort.

Proposal

Stop requesting the pipeline.details.manual_actions on page load, and instead shift this to be lazy loaded when the manual action buttons is clicked. This may require a seperate check of hasManualActions though this does not exist on the API yet and is being worked on in #360847 (closed)

We will be implementing this using the REST API.

Main Issue: #207994 (closed)