messy modlists collapse quickly

[yggdrasil75]

Describe the solution you'd like
tough feature request: collapsible merged mods.
so, I merge mods like planetary diversity and stellerotica and a few others. often with a minor amount of patching for those known to be built with eachother. I do this to try and make it eaiser to manage a mod list, so if I have to move pd up or down in the list, I dont have to move each individual pd mod, but the merge.
this works somewhat, but it keeps the left pane clogged, so I would like to request a "collapse" option for those merged mods, where the merged mods are included in each merge they are a part of (so long as the original collection still exists, or whatever is used to keep track of it)
it would also help "micropatch" mods to have it so that if I have a few mods, and I merge, then use that merge in another set, if I select all mods in the merge, it automatically selects the merge (assuming the merge is still valid I guess. probably use hash there) this way I can also see "oh, merge got unchecked, I need to update the patch"
related would be modgroups. take 2 mods and a known good patch, mark it so that any conflicts between the 3 "mods" are ignored in the conflict resolution screen automatically. I think this can be done with the "ignore" file, but I cant find any useful info on how that works.

additional context:
imagine scrolling through all of the planetary diversity mods and so you merge them. you dont want to unsubscribe because then you cant get updates and remerge as easily. if you could collapse them then you can just set up 1 item in the modlist easily.

alternatively: a manual collapsible section would work just as well, just adding your own collapsing sections instead of an automatically made one for merges.

[bcssov]

Notes:

• Needs to be broken down into smaller subsection features
• Needs revising (request too complex)
• Probably conflicts with certain other tasks or suggestions