Add save blocker when trying to delete a loaned prep

[CarolineDenis]

Fixes #1431

Checklist

• Self-review the PR after opening it to make sure the changes look good and
  self-explanatory (or properly documented)
• Add relevant issue to release milestone

Testing instructions

• Open an existing CO or create one
• Add a loanable prep type prep
• Create a loan with that CO and that prep
• Save the loan
• Go back to the CO form
• Try to delete the prep that is used in the loan
• Verify there is a safe blocker telling you that you cannot delete a prep that is on loan

TODO:

• Add isOnGift documentation and other interactions

[grantfitzsimmons]

• Verify there is a safe blocker telling you that you cannot delete a prep that is on loan

Screen.Recording.2025-03-27.at.9.28.16.PM.mov

[emenslin]

• Verify there is a safe blocker telling you that you cannot delete a prep that is on loan

This only works when the preparation is on loan, it does not work if the preparation is linked to any other interaction (e.g. gift, disposal, exchange out)

04-01_08.41.mp4

[CarolineDenis]

NOTES:
preparation.disposalPreparation returns: '/api/specify/disposalpreparation/?preparation=449'
449 being the prep id.
It doesn't seem that there is a simple way to know from prep if it's gifted or disposed or not.
Maybe we should add new attribute like isOnLoan for the other interactions?

[grantfitzsimmons]

Re: #6374 (comment)

Maybe we should add new attribute like isOnLoan for the other interactions?

See #5665, I think it's a great idea.

Also see this PR I've been thinking about since January: #6110

If you want to extend or take that over that's OK with me. I'll get to it eventually in any case 😄

[pashiav]

• Verify there is a safe blocker telling you that you cannot delete a prep that is on loan

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Works for other interactions other than loan now!

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Found that this workflow does not have a save blocker even though it recognizes that there is a linked Loan to the prep.
CO: https://ciscollections20250210-issue-1431.test.specifysystems.org/specify/view/collectionobject/40263/
Loan: https://ciscollections20250210-issue-1431.test.specifysystems.org/specify/view/loan/252/

1. View or create a CO with preps
2. Interactions -> Loan (or any other interaction) -> add prep from that CO -> Save
3. Use the navigator to go back to CO
4. Click SHOW_LOANS -> See that there is a loan record
5. Delete prep -> Save -> See error

Screen.Recording.2025-04-02.at.11.38.41.AM.1.mov

Specify 7 System Information - 2025-04-02T16_44_55.203Z.txt

[pashiav]

Approving since behavior is expected.

@CarolineDenis: "we do not fix the 'reload' issue it's like that everywhere in Sp"

[Areyes42]

• Verify there is a safe blocker telling you that you cannot delete a prep that is on loan

---

Looks good, I also tested deleting the prep when browsing in forms on QB and the blocker appeared 👍

fixed