Add support for including per-user settings

OpenSSH from version 8.2/8.2p1 (2020-02-14) onwards has Include support, specifically the following is at the top of the /etc/ssh/sshd_config file and settings take their first value so any .conf files in that directory will override the settings in the main sshd_config file.

Include /etc/ssh/sshd_config.d/*.conf

It would be nice if this YAML:

ssh_users:
  foo:
    present: true
    allow_tcp_forwarding: false
    authentication_methods: publickey password 
    password_authentication: true
    permit_tty: true
    pubkey_authentication: true    
    force_command: internal-sftp
ssh_groups:
  sudo:
    present: true
    allow_tcp_forwarding: true
    authentication_methods: publickey 
    password_authentication: false
    permit_tty: true
    pubkey_authentication: true

Resulted in the following lines being added to the end of /etc/ssh/sshd_config:

Include /etc/ssh/sshd_config.d/user/*.conf
Include /etc/ssh/sshd_config.d/group/*.conf

And the /etc/ssh/sshd_config.d/user/foo.conf and /etc/ssh/sshd_config.d/group/sudo.conf files being created containing:

Match group sudo
    AllowTCPForwarding: yes
    AuthenticationMethods: publickey 
    PasswordAuthentication: no

Match user foo
    AllowTCPforwarding: no
    AuthenticationMethods: publickey password 
    PasswordAuthentication: yes
    PermitTTY: yes
    PubkeyAuthentication: yes    
    ForceCommand: internal-sftp

See Match for all the allowed settings, only one template would be needed for both users and groups and potentially this could also be expanded for host and other things are are allowed in the future.

This would allow all the current specific Match blocks to be removed from the sshd_config template as the current results could be generated from variables in playbooks.