Proactively fail flow runs if there is an issue with flows storage

[cicdw]

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• adds new tests (if appropriate)
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What does this PR change?

This PR proactively fails flow runs from the local docker agent if there are issues with the Flow's storage, including an image pull error.

Why is this PR important?

Previously we simply logged the error and waited for Lazarus to come along and reschedule the flow, which typically just results in the flow run eventually failing after some time. Users expect an image pull error to immediately translate to a flow run failure. Closes #1395

[codecov]

Codecov Report

Merging #1729 into master will decrease coverage by 0.03%.
The diff coverage is 55.55%.