Feature request: Implement mechanism to save processed data to DANDI

[kabilar]

A discussion initiated by @francopestilli via email last year that I will paraphrase below.

Requirements:

1. We should determine how and where data will be stored once it has been processed on the BRAIN CONNECTS platform.
2. Ensure users' permissions are consistently respected across both the DANDI and BRAIN CONNECTS platforms.

Possible solution:

1. BRAIN CONNECTS could ask the user to provide the following information:
   1. DANDI API key?
   2. Should the data be open-access or embargoed?
   3. Which DANDI dataset should the data be saved to?
2. BRAIN CONNECTS would transform the data to comply with the BIDS spec.
3. BRAIN CONNECTS would then use the DANDI Client (https://github.com/dandi/dandi-cli) to transfer the data to the DANDI dataset.

cc @satra @ayendiki @tjgrafft @francopestilli