Add reencryption support

[norling]

As a user I want to be able to download files reencrypted with my public crypt4gh key.

A/C:

• [ ] A way of identifying if files are requested as decrypted or reencrypted
• [ ] Reading public keys from a secondary system (likely the database)
• [ ] Serving reencrypted files for download

See also neicnordic/sda-download#4

This can be done by using a new service that we are developing for re-encrypting headers.

[norling]

Hey team! Please add your planning poker estimate with Zenhub @aaperis @dbampalikis @jbygdell @kostas-kou @viklund

[blankdots]

duplicate of neicnordic/sensitive-data-archive#366

[viklund]

Closed because of duplicate.