For importing huddles we have to have unique huddle hashes.
Huddle hashes are extracted from the list of users participating
in a huddle. So to extract these user ids, we first use huddle
id to getting the matching recipient, and then we use subscription
to get the user ids from the recipient id.
Added tests for the same (tests slightly tweaked by tabbott).
In records the IDs like the realm_id and user_profile_id
of 'records.json' should be integers. This was missing in the
S3 backend and this commit fixes that.
Added tests for this as well.
For the emojis, In 'records.json', the record should contain
the attribute 'file_name', which was missing in the S3 backend.
This commit adds this attribute, as well as tests for the
records of uploads, avatars and emojis in both local and S3 backend.