Add error messages

[ghost]

What does this PR change?

Bumps the image tag with a new (semver compliant) Forecasting image that uses better http error codes and new more informative messages about things going wrong.

Does this PR rely on any other PRs?

https://github.com/kubecost/kubecost-modeling/pull/37

How does this PR impact users? (This is the kind of thing that goes in release notes!)

Users should now receive the correct message for unsupported aggregations and a 501, a 400 and more informative error for malformed requests, and a 503 and helpful message when a valid model is untrained (usually courtesy of upstream data issues)

Links to Issues or tickets this PR addresses or fixes

What risks are associated with merging this PR? What is required to fully test this PR?

Pretty minimal risk

How was this PR tested?

Locally!

Have you made an update to documentation? If so, please provide the corresponding PR.

n/a

[ghost]

/cherry-pick v2.0

[chipzoller]

/cherry-pick v2.0

[chipzoller]

FYI calling the cherry pick bot has some finicky permissions requirements; users who call for it must be added directly and cannot be part of a team.

[nealormsbee]

^ That would have been nice info to get when I asked why it seemed not to be working in the UI repo, rather than two links to a docs page that I'd already read.

Any chance you can add individuals from my team? Or do I need Thomas for that.

[chipzoller]

^ That would have been nice info to get when I asked why it seemed not to be working in the UI repo, rather than two links to a docs page that I'd already read.

We probably didn't know it was the case at that time because it was freshly implemented.

I can add individuals. Who should be added?

[nealormsbee]

@rayhatfield @wolfeaustin @jjarrett21 and myself, please and thank you.

[chipzoller]

Done