Group scrcpy options into a struct

The scrcpy() function accepts as many parameters as there are options.

To simplify, group all options in a separate struct.

app/src/scrcpy.h

@@ -3,6 +3,13 @@
 
 #include <SDL2/SDL_stdinc.h>
 
-SDL_bool scrcpy(const char *serial, Uint16 local_port, Uint16 max_size, Uint32 bit_rate);
+struct scrcpy_options {
+    const char *serial;
+    Uint16 port;
+    Uint16 max_size;
+    Uint32 bit_rate;
+};
+
+SDL_bool scrcpy(const struct scrcpy_options *options);
 
 #endif