Add options to configure tunnel host and port

In "adb forward" mode, by default, scrcpy connects to localhost:PORT,
where PORT is the local port passed to "adb forward". This assumes that
the tunnel is established on the local host with a local adb server
(which is the common case).

For advanced usage, add --tunnel-host and --tunnel-port to force the
connection to a different destination.

Fixes #2801 <https://github.com/Genymobile/scrcpy/issues/2801>
PR #2807 <https://github.com/Genymobile/scrcpy/pull/2807>

Signed-off-by: Romain Vimont <rom@rom1v.com>

app/src/options.c

@@ -19,6 +19,8 @@ const struct scrcpy_options scrcpy_options_default = {
         .first = DEFAULT_LOCAL_PORT_RANGE_FIRST,
         .last = DEFAULT_LOCAL_PORT_RANGE_LAST,
     },
+    .tunnel_host = 0,
+    .tunnel_port = 0,
     .shortcut_mods = {
         .data = {SC_MOD_LALT, SC_MOD_LSUPER},
         .count = 2,