Update FileFormats and Modalities to Enum subclasse

[nozomione]

Context

Related issue #1103

In previous issues #1065 and #1066, the FileFormats and Modalities classes were added to the enums directory to improve maintainability and reusability.

Problem or idea

In this issue, we will implement the approach from the related issue by converting FileFormats and Modalities classes into Enum subclasses and using them with models.TextChoices for field's choices.

Solution or next step

1. Convert FileFormats and Modalities into subclasses of Enum
2. Add a helper function that returns a list of tuples from a given enum forTextChoices
3. Update the relevant models to use models.TextChoices for their field choices