21.06-BETA.1 PR: https://github.com/truenas/middleware/pull/7011

Some thoughts for minimal testing for QE team:
1) Create minimum of three AFP shares with different paths - one of Time Machine, one a conventional file share, one a "home" share, and an SMB share with the "multiprotocol AFP" preset as well (same path as conventional file share).

2) Create a time machine backup on the AFP share, perform the migration, then verify that time machine is able to connect to the backup and continue where it left off without creating a new time machine backup.

3) In conventional share, test support for invalid characters. Write files with AFP metadata and verify that they are readable and has same name and shasum when read after the SMB migration (xattr -l on MacOS). Set color tags on files and verify that they are preserved post-migration.

4) For home share, confirm path is preserved. This needs to be tested twice, once with existing SMB home share and once without

Repeat steps (1-4) with standalone server, AD-joined server, and LDAP-bound server.

5) When AFP shares are migrated to SMB, the "aapl extensions" box in Services->SMB must be checked post-migration. Trying to remove should result in a validation error.

6) MacOS client should no longer see an _afpovertcp._tcp. SRV record over mDNS. (can be queried via dns-sd on MacOS).

7) SMB share should have `afp` key set.

<note – this will be updated as I review PR>

None PR: https://github.com/truenas/middleware/pull/6936

None PR: https://github.com/truenas/middleware/pull/6935

21.06 PR: https://github.com/truenas/middleware/pull/6919