[WIP] Enthusiastic Promotor for Worker Tool images

[mjhilton]

This PR introduces a PowerShell script which can perform Enthusiastic Promotion for Worker Tools images, by:

1. [Done] Finding any unpromoted releases ("promotion candidates") in the target Octopus project
2. [To-do] Determining which images are currently cached on the Production Dynamic Workers, by:
   a. Finding the most recent fully-promoted Dynamic Worker image (promoted to all Octopus Cloud regions)
   b. Determining which docker images are cached on that Dynamic Worker image, by cross-referencing its deployment artifacts
3. [To-do] Filtering out any promotion candidates whose corresponding docker image is not cached on the current Dynamic Worker image

Once the candidate releases have been filtered down to those that are fully cached on the Dynamic Workers, we trigger a promotion of the candidate to Production, making it available to customers on DockerHub.

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1 out of 2 committers have signed the CLA.

✅ mjhilton
❌ Yihao

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