nmcli: avoid changed status for most cases with VPN connections (#5126)

* nmcli: avoid changed status for most cases with VPN connections

Follow-up https://github.com/ansible-collections/community.general/pull/4746

* `nmcli connection show` includes vpn.service-type but not vpn-type.
  Switching to vpn.service-type removes unneeded diffs while keeping
  the same functionality, as vpn-type is an alias of vpn.service-type
  per nm-settings-nmcli(1).

  NetworkManager also adds `org.freedesktop.NetworkManager.` prefix for
  known VPN types [1]. The logic is non-trivial so I didn't implement it
  in this commit. If a user specifies `service-type: l2tp`, changed will
  be always be True:

    -    "vpn.service-type": "org.freedesktop.NetworkManager.l2tp"
    +    "vpn.service-type": "l2tp"

* The vpn.data field from `nmcli connection show` is sorted by keys and
  there are spaces around equal signs. I added codes for parsing such
  data.

Tests are also updated to match outputs of nmcli commands.

[1] https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/blob/1.38.4/src/libnm-core-impl/nm-vpn-plugin-info.c#L619

* Add changelog

* Some suggested changes

* Make space stripping more flexible - works for cases without equal
  signs.
* Keep vpn.data in a test case with no spaces

* nmcli: allow any string for vpn service-type

plugins/modules/net_tools/nmcli.py

@@ -923,7 +923,6 @@ options:
                 description: This defines the service type of connection.
                 type: str
                 required: true
-                choices: [ pptp, l2tp ]
             gateway:
                 description: The gateway to connection. It can be an IP address (for example C(192.0.2.1))
                     or a FQDN address (for example C(vpn.example.com)).
@@ -949,7 +948,7 @@ options:
             ipsec-enabled:
                 description:
                     - Enable or disable IPSec tunnel to L2TP host.
-                    - This option is need when C(service-type) is C(l2tp).
+                    - This option is need when C(service-type) is C(org.freedesktop.NetworkManager.l2tp).
                 type: bool
                 choices: [ yes, no ]
             ipsec-psk:
@@ -1350,7 +1349,7 @@ EXAMPLES = r'''
     conn_name: my-vpn-connection
     vpn:
         permissions: "{{ ansible_user }}"
-        service-type: l2tp
+        service-type: org.freedesktop.NetworkManager.l2tp
         gateway: vpn.example.com
         password-flags: 2
         user: brittany
@@ -1670,7 +1669,7 @@ class Nmcli(object):
                 for name, value in self.vpn.items():
                     if name == 'service-type':
                         options.update({
-                            'vpn-type': value,
+                            'vpn.service-type': value,
                         })
                     elif name == 'permissions':
                         options.update({
@@ -2100,8 +2099,8 @@ class Nmcli(object):
                 if key == self.mtu_setting and self.mtu is None:
                     self.mtu = 0
                 if key == 'vpn.data':
-                    current_value = list(map(str.strip, current_value.split(',')))
-                    value = list(map(str.strip, value.split(',')))
+                    current_value = sorted(re.sub(r'\s*=\s*', '=', part.strip(), count=1) for part in current_value.split(','))
+                    value = sorted(part.strip() for part in value.split(','))
             else:
                 # parameter does not exist
                 current_value = None