[Feat|Fix|Improvement] (All): Continue building the basic structure.

Feat: implement MG_Impl/Buffer
Feat: implement MG_State/ErrorState and integrate it into MG_State/GLContext
Feat: add buffer deletion management
Feat: introduce `INSERTION_POINT` (https://github.com/MobileGL-Dev/MobileGLCodeManager)
Feat: add tests about MG_Impl/Buffer and buffer deletion feature
Feat: add several converters
Fix: fix some compiling errors
Fix: fix some incorrect behaviors in MG_State/Buffer
Improvement: remove some current statements at the beginning of the source file, which will be added uniformly soon
Improvement: optimize some naming

MobileGL/MG_Impl/GLImpl/Buffer/Validators.h

@@ -0,0 +1,10 @@
+#pragma once
+
+namespace MobileGL::MG_Impl::GLImpl {
+	namespace BufferImpl {
+		bool ValidateBufferTarget(BufferTarget target);
+		bool ValidateBufferName(Uint index);
+		bool ValidateBufferUsage(BufferUsage usage);
+		bool ValidateBufferMappingAccess(BufferMappingAccessBit accessBits);
+	}
+}