Implement virDomainQemuMonitorCommandWithFiles() override

With libvirt-8.2.0 there's a new API:
virDomainQemuMonitorCommandWithFiles(). Since the API has both
input and output arguments we need to provide an alternative
implementation. Moreover, since FD passing works only on
UNIX-like systems we can query the returned FDs for their flags
and construct mode for python File object.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

libvirt-qemu-override.py

@@ -1,5 +1,5 @@
 # Manually written part of python bindings for libvirt-qemu
-from typing import Any, Callable, Dict
+from typing import Any, Callable, Dict, List, IO
 
 
 def _dispatchQemuMonitorEventCallback(conn: libvirt.virConnect, dom: libvirt.virDomain, event: str, seconds: int, micros: int, details: str, cbData: Dict[str, Any]) -> int:
@@ -38,3 +38,32 @@ def qemuMonitorEventRegister(conn: libvirt.virConnect, dom: libvirt.virDomain, e
         raise libvirt.libvirtError('virConnectDomainQemuMonitorEventRegister() failed')
     conn.qemuMonitorEventCallbackID[ret] = opaque  # type: ignore
     return ret
+
+def qemuMonitorCommandWithFiles(domain: libvirt.virDomain, cmd: str, files: List[int] = [], flags: int = 0) -> (str, List[IO]):
+    """This API is QEMU specific, so it will only work with hypervisor
+    connections to the QEMU driver with local connections using the unix
+    socket.
+
+    Send an arbitrary monitor command @cmd with file descriptors @files to
+    domain through the QEMU monitor and optionally return a list of files
+    in the returned tuple. There are several requirements to safely
+    and successfully use this API:
+
+   - A @cmd that queries state without making any modifications is safe
+   - A @cmd that alters state that is also tracked by libvirt is unsafe,
+     and may cause libvirtd to crash
+   - A @cmd that alters state not tracked by the current version of
+     libvirt is possible as a means to test new qemu features before
+     they have support in libvirt, but no guarantees are made to safety
+
+    If VIR_DOMAIN_QEMU_MONITOR_COMMAND_HMP is set, the command is considered to
+    be a human monitor command and libvirt will automatically convert it into
+    QMP if needed.  In that case the @result will also be converted back from
+    QMP.
+
+    Returns a tuple consisting of the string output from @cmd and a list of
+    files respectively."""
+    ret = libvirtmod_qemu.virDomainQemuMonitorCommandWithFiles(domain._o, cmd, files, flags)
+    if ret is None:
+        raise libvirt.libvirtError('virDomainQemuMonitorCommandWithFiles() failed')
+    return ret