Remove 'nova-xvpvncproxy'

This legacy service is no longer used and was deprecated during the
Stein cycle [1]. It's time to say adios and remove them in their
entirety. This is pretty straightforward, with the sole exception of
schema for the 'remote-consoles' API, which has to continue supporting
requests for type 'xvpvnc' even if we can't fulfil those requests now.

[1] https://review.opendev.org/#/c/610076/

Part of blueprint remove-xvpvncproxy

Depends-On: https://review.opendev.org/695853
Change-Id: I2f7f2379d0cd54e4d0a91008ddb44858cfc5a4cf
Signed-off-by: Stephen Finucane <sfinucan@redhat.com>

api-ref/source/parameters.yaml

@@ -5284,7 +5284,7 @@ os-getVNCConsole:
   type: object
 os-getVNCConsole-type:
   description: |
-    The type of VNC console. The valid values are ``novnc`` and ``xvpvnc``.
+    The type of VNC console. The only valid value is ``novnc``.
   in: body
   required: true
   type: string
@@ -5833,7 +5833,7 @@ remote_console_protocol:
   type: string
 remote_console_type:
   description: |
-    The type of remote console. The valid values are ``novnc``, ``xvpvnc``,
+    The type of remote console. The valid values are ``novnc``,
     ``rdp-html5``, ``spice-html5``, ``serial``, and ``webmks``. The type
     ``webmks`` is added since Microversion ``2.8``.
   in: body

api-ref/source/servers-action-remote-consoles.inc

@@ -175,9 +175,6 @@ Gets a VNC console for a server.
 
 Specify the ``os-getVNCConsole`` action in the request body.
 
-The supported connection types are ``novnc``, ``xvpvnc``. Such as connect
-with ``novnc``, set ``type`` parameter to ``novnc``.
-
 Normal response codes: 200
 
 Error response codes: badRequest(400), unauthorized(401), forbidden(403), itemNotFound(404),

api-ref/source/servers-remote-consoles.inc

@@ -17,9 +17,7 @@ The API provides a unified request for creating a remote console. The user can
 get a URL to connect the console from this API. The URL includes the token
 which is used to get permission to access the console. Servers may support
 different console protocols. To return a remote console using a specific
-protocol, such as RDP, set the ``protocol`` parameter to ``rdp``. For the same
-protocol, there may be different connection types such as ``vnc protocol and
-novnc type`` or ``vnc protocol and xvpvnc type``.
+protocol, such as RDP, set the ``protocol`` parameter to ``rdp``.
 
 Normal response codes: 200