[Bug]: InputDataAgent always uses FileCatalogClient

### Search before creating an issue

- [x] I have searched existing issues and confirmed this is not a duplicate

### Bug Description

The `InputDataAgent` directly instantiates the `FileCatalogClient` instead of going through `FileCatalog`, making it impossible to use the `InputDataAgent` when the main file catalog of a DIRAC deployment is a `RucioFileCatalog`.

### Steps to Reproduce

https://github.com/DIRACGrid/DIRAC/blob/36806a11894e7330005b9fceaa42444a7ffb64f7/src/DIRAC/TransformationSystem/Agent/InputDataAgent.py#L48

### Expected Behavior

Use `FileCatalog` to obtain the correct client for the current configuration.

### Actual Behavior

_No response_

### Environment

_No response_

### Relevant Log Output

```shell

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### Additional Context

_No response_