Add Night Vision scopes keybinding to MCM menu (DIK_M)

[axet]

Hello!

Game has hardcoded keybinding for night vision scopes. This patch add MCM settings for keybinding for project "GAMMA/mods/G.A.M.M.A. Keybinds fixes".

If you want a pull request I can create one.

diff --git a/gamedata/scripts/bas_nvg_scopes.script b/gamedata/scripts/bas_nvg_scopes.script
index a36db7b..4b87b40 100644
--- a/gamedata/scripts/bas_nvg_scopes.script
+++ b/gamedata/scripts/bas_nvg_scopes.script
@@ -1,4 +1,4 @@
-local switch = DIK_keys.DIK_M
+switch = DIK_keys.DIK_M
 
 local nvg_type = 2
 local nvg_active
diff -ru --new-file a/gamedata/scripts/bas_nvg_scopes_mcm.script b/gamedata/scripts/bas_nvg_scopes_mcm.script
--- a/gamedata/scripts/bas_nvg_scopes_mcm.script	1970-01-01 03:00:00.000000000 +0300
+++ b/gamedata/scripts/bas_nvg_scopes_mcm.script	2023-07-11 10:44:43.473200078 +0300
@@ -0,0 +1,30 @@
+local op = { id = "nvm_keys", sh = true, gr = {
+         { id = "ui_keybind", type = "key_bind", val = 2, def = DIK_keys.DIK_M },
+       }
+     }
+
+function get_config(key)
+  local opt = ui_mcm and ui_mcm.get("nvm_keys/"..key)
+  if opt ~= nil then return opt else return defaults[key] end
+end
+
+function defaults(key)
+  for k,v in pairs(op["gr"]) do
+    if (op["gr"][k]["id"] == key ) then print(op["gr"][k]["def"]) end
+  end
+end
+
+function on_mcm_load()
+  return op
+end
+
+function on_option_change(mcm)
+  if mcm then
+      bas_nvg_scopes.switch = get_config("ui_keybind")
+  end
+end
+
+function on_game_start()
+  RegisterScriptCallback("on_option_change", on_option_change)
+  on_option_change(ui_mcm and ui_mcm.key_hold)
+end