x11: add --x11-wid-title option

This deliberately wasn't being done when mpv was embedded
(fbccddb48b). There are some applications
that would benefit from mpv setting a title since they don't do so
themselves (such as tabbed), but at the same time some others would
probably rather not have this behavior (like smplayer). Add an option
that allows an embedded mpv to set the title if the user wishes.
Fixes #11528.

options/options.c

@@ -181,6 +181,7 @@ static const m_option_t mp_vo_opt_list[] = {
         {"no", 0}, {"yes", 1}, {"fs-only", 2}, {"never", 3})},
     {"x11-present", OPT_CHOICE(x11_present,
         {"no", 0}, {"auto", 1}, {"yes", 2})},
+    {"x11-wid-title", OPT_BOOL(x11_wid_title)},
 #endif
 #if HAVE_WAYLAND
     {"wayland-content-type", OPT_CHOICE(content_type, {"auto", -1}, {"none", 0},

options/options.h

@@ -32,6 +32,7 @@ typedef struct mp_vo_opts {
     int x11_netwm;
     int x11_bypass_compositor;
     int x11_present;
+    bool x11_wid_title;
     bool cursor_passthrough;
     bool native_keyrepeat;