Change name of image tag during astro deploy

[collinmcnulty]

• [X] I have checked that a similar feature request does not already exist.

✍️ Is your feature request related to a problem? Please describe.

Productboard Customers have internal versioning schemes for their images, such as semver, but the Astro UI does not have a way to deploy anything other than deploy-[date].

🧩 Describe the solution you'd like

An --image-tag flag that allowed the customer to specify the tag they want to have on the image would be ideal.

🤔 Describe alternatives you've considered

It's also possible that we could require them to docker build and tag the image, and then just not rename the image when astro deploy is called. (This is how it works on Software.)

Is your feature request specific to a particular Astronomer Platform?

• [X] Astro
• [ ] Software
• [ ] None/Unknown

[cmarteepants]

As per https://astronomer.slack.com/archives/C01UA03TPV1/p1688744637169129?thread_ts=1687551445.535769&cid=C01UA03TPV1, when doing an astro deploy -i my-repo-name:my-image-name, we should only override my-repo-name with the Astronomer Registry.

If the tag being passed only contains something, we can either assume that that is tag, and retag with astro-repo-name:something, or throw an error saying the image name is invalid.

[cmarteepants]

We also shouldn't accept latest as a tag.