finish CKtexture writer

- finish CKTexture writer
- add std::enable_if for CKStateChunk::ReadIdent&WriteIdent to limit it in enum type.
- fix error function calling in CKBitmapData writer.
- let CKTexture reader mor formal for mipmap.
- fix CKStateChunk ReadBuffer redirect guideline.
- add a stupid height and width getter for CKBitmapData to serve CKTexture using.

LibCmo/CK2/CKBitmapData.hpp

@@ -106,6 +106,17 @@ namespace LibCmo::CK2 {
 		*/
 		CKSTRING GetSlotFileName(CKDWORD slot) const;
 
+		/**
+		 * @brief Get first valid image's width.
+		 * @return 0 if no valid image.
+		*/
+		CKDWORD GetWidth() const;
+		/**
+		 * @brief Get first valid image's height.
+		 * @return 0 if no valid image
+		*/
+		CKDWORD GetHeight() const;
+
 #pragma endregion
 
 #pragma region Not important funcs