feat(gx): add incomplete 'CGxDeviceGLSDL' (#2)

* chore(build): add vendored SDL 3.0.0 library

* chore(build): add vendored glew-cmake-2.2.0 library

* feat(console): in the presence of -opengl launch flag, change GxApi to OpenGl

* feat(gx): add uncompleted CGxDeviceGLSDL targeting Windows and Linux

* chore(build): change SDL3 linkage from shared (bad) to to static (good)

vendor/sdl-3.0.0/cmake/android/FindSdlAndroid.cmake

@@ -0,0 +1,103 @@
+#[=======================================================================[
+
+FindSdlAndroid
+----------------------
+
+Locate various executables that are essential to creating an Android APK archive.
+This find module uses the FindSdlAndroidBuildTools module to locate some Android utils.
+
+
+Imported targets
+^^^^^^^^^^^^^^^^
+
+This module defines the following :prop_tgt:`IMPORTED` target(s):
+
+`` SdlAndroid::aapt2 ``
+   Imported executable for the "android package tool" v2
+
+`` SdlAndroid::apksigner``
+   Imported executable for the APK signer tool
+
+`` SdlAndroid::d8 ``
+   Imported executable for the dex compiler
+
+`` SdlAndroid::zipalign ``
+   Imported executable for the zipalign util
+
+`` SdlAndroid::adb ``
+   Imported executable for the "android debug bridge" tool
+
+`` SdlAndroid::keytool ``
+   Imported executable for the keytool, a key and certificate management utility
+
+`` SdlAndroid::zip ``
+   Imported executable for the zip, for packaging and compressing files
+
+Result variables
+^^^^^^^^^^^^^^^^
+
+This module will set the following variables in your project:
+
+`` AAPT2_BIN ``
+   Path of aapt2
+
+`` APKSIGNER_BIN ``
+   Path of apksigner
+
+`` D8_BIN ``
+   Path of d8
+
+`` ZIPALIGN_BIN ``
+   Path of zipalign
+
+`` ADB_BIN ``
+   Path of adb
+
+`` KEYTOOL_BIN ``
+   Path of keytool
+
+`` ZIP_BIN ``
+   Path of zip
+
+#]=======================================================================]
+
+cmake_minimum_required(VERSION 3.7)
+
+if(NOT PROJECT_NAME MATCHES "^SDL.*")
+  message(WARNING "This module is internal to SDL and is currently not supported.")
+endif()
+
+find_package(SdlAndroidBuildTools MODULE)
+
+function(_sdl_android_find_create_imported_executable NAME)
+  string(TOUPPER "${NAME}" NAME_UPPER)
+  set(varname "${NAME_UPPER}_BIN")
+  find_program("${varname}" NAMES "${NAME}" PATHS ${SDL_ANDROID_BUILD_TOOLS_ROOT})
+  if(EXISTS "${${varname}}" AND NOT TARGET SdlAndroid::${NAME})
+    add_executable(SdlAndroid::${NAME} IMPORTED)
+    set_property(TARGET SdlAndroid::${NAME} PROPERTY IMPORTED_LOCATION "${${varname}}")
+  endif()
+endfunction()
+
+if(SdlAndroidBuildTools_FOUND)
+  _sdl_android_find_create_imported_executable(aapt2)
+  _sdl_android_find_create_imported_executable(apksigner)
+  _sdl_android_find_create_imported_executable(d8)
+  _sdl_android_find_create_imported_executable(zipalign)
+endif()
+
+_sdl_android_find_create_imported_executable(adb)
+_sdl_android_find_create_imported_executable(keytool)
+_sdl_android_find_create_imported_executable(zip)
+include(FindPackageHandleStandardArgs)
+
+find_package_handle_standard_args(SdlAndroid
+  VERSION_VAR
+  REQUIRED_VARS
+    AAPT2_BIN
+    APKSIGNER_BIN
+    D8_BIN
+    ZIPALIGN_BIN
+    KEYTOOL_BIN
+    ZIP_BIN
+)