Fix minor bugs in MIRI LRS spec3 master_background

[stscijgbot-jp]

Issue JP-3792 was created on JIRA by Melanie Clarke:

While updating some MIRI LRS regression tests for JP-2928, I noticed a few small bugs in the master background correction step in spec3:

1. If a single spectrum is passed to combine1d, the wavelength array for the input spectrum is sorted in place instead of being copied for the output spectrum, then sorted. For MIRI, this has the effect of reversing the order of the wavelength array compared to the order of the data, which corrupts the spectrum in the output "combined" product.

2. The 'mbsub' suffix is used in calwebb_spec3 for the master background output, but it is not recorded as a known suffix, so it does not get properly removed for the next product in the pipeline.

3. In the master_background step, when a user background is provided, there are a couple small bugs relating to changes to the ModelContainer in JP-3721. There was an overlooked container.update call that crashed if the input was also a ModelContainer, since ModelContainers no longer have their own metadata (so no update function exists). There was also a place where a single model was passed to a function that expected a container when {}save_background=True{}, also causing a crash.

[stscijgbot-jp]

Comment by Melanie Clarke on JIRA:

Proposed fixes are in PR https://github.com/spacetelescope/jwst/pull/8927](https://github.com/spacetelescope/jwst/pull/8927), along with the updates to the regression tests.

[stscijgbot-jp]

Comment by David Law on JIRA:

Tagging Greg Sloan and Andreea Petric

[stscijgbot-jp]

Comment by David Law on JIRA:

Remove the extra trailing character from the link

[stscijgbot-jp]

Comment by Melanie Clarke on JIRA:

Sorry about that! I fixed the link in the message above.

[stscijgbot-jp]

Comment by Melanie Clarke on JIRA:

Fixed by #8927