Update paths for MTA radiation reorg

[jeanconn]

Description

Update paths for MTA radiation reorganization.

With regard to process, I reviewed the MTA doc noting path reorganization, focused mostly on summary, GOES, and ACE products, and manually reviewed the configuration data for replan central to update these paths. The supported / new paths work now. The intent is that this PR proactively updates the page so content will still work when the now-deprecated MTA pages are eventually removed - if anything has been missed in the replan central review and becomes apparent when the upstream resources are no longer available, we'll update any missed paths in a future PR.

I also removed references to two images provided by MTA in the config, as they were no longer used.

Interface impacts

The ACE plot displayed on the Replan Central page will now have a white instead of black background, as the upstream page from MTA is now only available in that scheme.

Functional testing

I put an on-the side job up at
https://cxc.cfa.harvard.edu/mta/ASPECT/arc3-pr95/

[taldcroft]

LGTM for code.

Of note to put in the description:

• Two mta_*_img config definitions removed since they were unused.
• Interface impact (upstream) that the ACE plot has changed to light mode (or maybe just colors reversed). I'm not sure this has been widely noted, but for a plot that everyone has been looking at for 25 years it should be mentioned.

[taldcroft]

Also, you should document your process for finding paths that need to be updated. I see that all the diffs look reasonable but it's hard to know if this is complete.

[jeanconn]

I've flushed out the Description though I had planned to link to the MTA google doc in the FSDS.

[taldcroft]

Thanks looks good.