Align Project model with metadata schema (remove funder)

[coderTanisha22]

Change(s)

Change Type: Removed / Updated
Change Category: Internal

Changelog Entry:
Align the Project model with the metadata schema.

• Removed the 'funder' field from the 'Project' model and its 'RelationshipConfig', as it is not part of the metadata schema.
• Ensured consistent use of 'total_cost_euros' (instead of deprecated 'total_cost_euro').
• Updated project router tests to reflect the removal of the 'funder' field.

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How to Test

1. Navigate to the 'src' directory

2. Run project-specific tests:
   pytest -q tests/routers/resource_routers/test_router_project.py

3. (Optional) Run broader router tests:
   pytest -q tests/routers/resource_routers

All tests should pass successfully.

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Checklist

• Tests have been added or updated to reflect the changes
• Documentation has not been updated (not required for this change)
• A self-review has been conducted checking:
  • No unintended changes have been committed
  • The changes in isolation seem reasonable
• All CI checks pass (or locally verified)
• The PR title matches the changelog entry's one-line description

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Related Issues

Closes #492

[coderTanisha22]

@PGijsbers Hi! I've addressed issue #492 with this PR. Would appreciate a review when you have time. Thanks!