Add tentative resource allocation

[ananyo141]

Description

This PR introduces the functionality of tentative resource allocation. It adds an is_tentative checkbox to the resource allocation form. This allows users to mark an allocation as tentative.

Additionally, a patch is included to convert all existing resource allocations to 'Confirmed'. This is a one-time migration to ensure that all previous allocations are correctly classified.

Relevant Technical Choices

• Data & UI: An is_tentative boolean field was added to the Resource Allocation model, controlled by a checkbox in the user interface.
• Data Migration: A patch was implemented to migrate all existing allocations to a "Confirmed" state, ensuring data consistency.
• Backend: The backend logic was updated to correctly save and retrieve the is_tentative status when creating or editing allocations.

Testing Instructions

• Create Tentative: Check "Is Tentative", save, and verify the allocation is "Tentative".
• Create Confirmed: Leave "Is Tentative" unchecked, save, and verify the allocation is "Confirmed".
• Edit to Confirmed: Open a "Tentative" allocation, uncheck the box, save, and verify it's now "Confirmed".
• Edit to Tentative: Open a "Confirmed" allocation, check the box, save, and verify it's now "Tentative".
• Verify Migration: Run the patch and confirm in the database that all pre-existing allocations are now "Confirmed".

Additional Information:

Screenshot/Screencast

Checklist

• I have carefully reviewed the code before submitting it for review.
• This code is adequately covered by unit tests to validate its functionality.
• I have conducted thorough testing to ensure it functions as intended.
• A member of the QA team has reviewed and tested this PR (To be checked by QA or code reviewer)

Ref https://github.com/rtCamp/erp-rtcamp/issues/2470