feat(lua): Port of NodeMCU Lua53 read-only tables (#2994)

* chore(lua): revert useless c light function change

This change was part of the eLua LTR patches (based on 5.1), whereby this feature was already integrated in Lua 5.2.

* feat(lua): port of NodeMCU Lua53 read-only tables

# Conflicts:
#	radio/src/lua/CMakeLists.txt
#	radio/src/lua/api_general.cpp

* fix(nv14): missing SDRAM definition

* fix: l_mathop

* fix: use float functions in drawPower()

* fix: ltable resize

* fix: correct name is "bit32"

* fix: first Lua context must be closed last

As the lookup cache is attached to that one

* Revert to Lua using double

* Ensure byte-code compatibility

* Fix possible compatibility issue with `lua_typename`/`luaL_typename`

* Fix Bitmap symbol table

* Re-add table lib for COLORLCD

radio/src/lua/api_filesystem.h

@@ -19,8 +19,8 @@
  * GNU General Public License for more details.
  */
 
-#define DIR_METATABLE "directory metatable"
+#include "definitions.h"
 
-void registerDirIter(lua_State* L);
-int luaDir(lua_State* L);
-int luaFstat(lua_State* L);
+#define DIR_METATABLE "DIR*"
+
+EXTERN_C(LUALIB_API int luaopen_etxdir(lua_State* L));