Integrate a Mass Transfer feature

[medihack]

In contrast to batch transfer, where you select patients by patient ID, mass transfer allows you to specify only a time range and, optionally, other filters such as modality or institution name to transfer large amounts of DICOM data (thousands of studies) between two systems.

The core idea is in Volume Export Pipeline as a Dagster pipeline and needs to be transferred to RADIS.

• New navbar item "Mass Transfer"
• A Django formset to specify multiple filters (see README of Volume Export Pipeline)
• The existing job/task model may not be a good fit (maybe too many tasks); investigate better options (e.g., daily partitions).
• Mass transfer tasks should always have the lowest priority (or maybe it's own worker?!).

[medihack]

It's better not to close the issues manually; instead, add "Closes #289" to the PR description (or in a comment). As soon as the PR is merged, the issue will be automatically closed. Also, it is clear which PR is associated with the issue; a note will be automatically added here. Try it out (I think it even works when you add it afterwards).