Remove the name from Dataset and replace it with an id

This makes it easier to generate application-level atom paths that are
manageable. Datasets are given unique IDs at generation time.
1 job for v2 in 42 seconds
Status Job ID Name Coverage
  Test
failed #9125
test

00:00:42

 
Name Stage Failure
failed
test Test
2019/06/19 08:03:30 sh: restic -r /tmp/404366414/repo --password-file /tmp/restic-pw-017844053 snapshots --json --tag dataset_id=db1cf6bea108d29cf77014aeabce5c5b --tag backup_id=cff89cc649d1e0795a4b92e79d1198dd
2019/06/19 08:03:31 sh: (restic -r /tmp/404366414/repo --password-file /tmp/restic-pw-017844053 restore --target /tmp e4c2a067 1>&2 && cat /tmp/STDIN_source1_db1cf6bea108d29cf77014aeabce5c5b) | lz4c -d - - | (read row ; test "x$row" = xdata)
/bin/sh: 1: lz4c: not found
restoring <Snapshot e4c2a067 of [/STDIN_source1_db1cf6bea108d29cf77014aeabce5c5b] at 2019-06-19 08:03:28.973214673 +0000 UTC by @runner-1fc9a9d2-project-359-concurrent-0> to /tmp
--- FAIL: TestRestic_Stream_Compress (5.58s)
repository_restic_test.go:125: Restore exit status 1
FAIL
FAIL git.autistici.org/ai3/tools/tabacco 16.094s
ERROR: Job failed: exit code 1