[core] database feature v1

[DSkywalk]

Objective

To facilitate the use of the emulator for new users by using a clean database.

Tasks

• [x] Change the "joystick" option to "auto"
• [x] Create an database of keymaps using clean-cpc-db info work #112
• [x] python script to build entries database from RMP comunity shared files.
• [x] add commands/loader support
• [x] add WAIT token to kbdauto.

If the game exists, configure the keys (and loader) to the user automatically.

example RMP => DB:

TODO v2:

Add input descriptors, thx to @jdgleaver for his help :+1:

e.g. so if you do something like:

   struct retro_input_descriptor desc[] = {
      { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_LEFT,   "Left" },
      { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_UP,     "Up" },
      { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_DOWN,   "Down" },
      { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_RIGHT,  "Right" },
      { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_B,      "Fire" },
      { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_A,      "Jump" },
      { 0 },
   };

Then RetroPad X, Y, etc. will be unbound in the frontend, but the user can still manually bind them to Fire, Jump, etc. if they want to move things around (and only those named inputs will be available when remapping a button)