ENHANCE: split DataType, DataFormat, EnumString from other files

Context

Data, DataType and DataFormat are all defined in the same file, leading to long and confusing code as well as unused inclues. This MR aims at fixing this by providing a seperate file for Data, DataType and DataFormat.

the Same goes for Attributes And EnumString.

Detailed major modifications

• [add] DataType.hpp/DataType.cpp
• [add] DataFormat.hpp/DataFormat.cpp
• [add] EnumString.hpp
• [enhance] Make NativeType constexpr, add NativeType_v helper variable template
• [upd] Change some includes
• [fix] warning in half.hpp due to a space between the quotation marks and the suffix identifier '_h' in the literal operator declaration