vaxis: implement osc2 set title

Signed-off-by: Tim Culverhouse <[e-mail]>

src/ctlseqs.zig

···
 pub const strikethrough_reset = "\x1b[29m";
 
 // OSC sequences
+pub const osc2_set_title = "\x1b]2;{s}\x1b\\";
 pub const osc8 = "\x1b]8;{s};{s}\x1b\\";
 pub const osc8_clear = "\x1b]8;;\x1b\\";
 pub const osc9_notify = "\x1b]9;{s}\x1b\\";

src/vaxis.zig

···
                 );
             }
         }
+
+        /// sets the window title
+        pub fn setTitle(self: *Self, title: []const u8) !void {
+            if (self.tty == null) return;
+            try std.fmt.format(
+                self.tty.?.buffered_writer.writer(),
+                ctlseqs.osc2_set_title,
+                .{title},
+            );
+        }
     };
 }