netcmd: service-account commands

Adds the following commands:

samba-tool service-account list [--json]
samba-tool service-account create --name <name> --dns-host-name <hostname> --managed-password-interval <interval>
samba-tool service-account view --name <name|Dn>
samba-tool service-account modify --name <name|Dn> --dns-host-name <hostname> --managed-password-interval <interval> --group-msa-membership=<sddl>
samba-tool service-account remove --name <name|Dn>
samba-tool service-account group-msa-membership show --name <name|Dn>
samba-tool service-account group-msa-membership add --name <name|Dn> --principal <name|Dn>
samba-tool service-account group-msa-membership remove --name <name|Dn> --principal <name|Dn>

Carries on from !3511 (closed)

Checklist

• Commits have Signed-off-by: with name/author being identical to the commit author
• (optional) This MR is just one part towards a larger feature.
• (optional, if backport required) Bugzilla bug filed and BUG: tag added
• Test suite updated with functionality tests
• Test suite updated with negative tests
• Documentation updated
• CI timeout is 3h or higher (see Settings/CICD/General pipelines/ Timeout)

Reviewer's checklist:

• There is a test suite reasonably covering new functionality or modifications
• Function naming, parameters, return values, types, etc., are consistent and according to README.Coding.md
• This feature/change has adequate documentation added
• No obvious mistakes in the code