[Feature]: Assigning input sandboxes to jobs

[aldbr]

User Story

As a developer, I want diracx-tasks to assign input sandboxes to jobs once they reach the router, so that users can easily retrieve the input sandboxes when needed.

Feature Description

Here is how it's done in DIRAC: https://github.com/DIRACGrid/DIRAC/blob/15976973cb583d0232acf3e481b7bc53173c83c4/src/DIRAC/WorkloadManagementSystem/Executor/JobSanity.py#L43-L67

Here we would rely on diracx-tasks to replace the DIRAC Executors.
Note: it requires diracx-tasks to be implemented.

Definition of Done

• Input sandboxes are assigned by a diracx task
• Unit tests (general case, unknown input sandbox provided, ...)

Alternatives Considered

No response

Related Issues

No response

Additional Context

No response