Merge dmUpdate branch into main

[rem1776]

Description Brings over the changes from dmUpdate into the main branch. I rebased the branch to get rid of duplicate commits and also to clean up the formatting of the commit messages, this way we can merge this instead of squashing it into one commit.

After the rebase I ran a diff so these changes should be exactly whats in dmUpdate, content-wise (minus the uml diagrams).

How Has This Been Tested? make distcheck on amd box

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [x] Any dependent changes have been merged and published in downstream modules
• [x] New check tests, if applicable, are included
• [x] make distcheck passes

[thomas-robinson]

Thank you to everyone who contributed to this project especially @uramirez8707 @rem1776 @ngs333 @ganganoaa . Your contributions over the YEARS have been invaluable to the improvement of the diag manager code. Now let's merge this beast in and deal with the bugs lol.