SLIDE v2 update

[ElektrikAkar]

This update is the first step to SLIDE v2. It includes performance improvements and additional auxillary functions. Major changes are:

• Most of the functions, especially estimateOCVparameters() should be faster now.
• It should be able to run on different platfroms/compilers through CMake.
• Name capitalisation bugs are fixed.
• Documentation is updated.
• Auxillary functions and data types are added (such as fixed_data, linspace, logspace, linstep, etc.).
• Parallelisation is wrapped into slide::run function.
• Arrangement of files is changed, data, results, and docs folders are created.
• Required C++ standard is upgraded from C++11 to C++17.
• Modern C++ features are now incorporated into the code.
  • Instead of increasing stack memory to hold large arrays, now we use std::vector.
  • Most of the raw arrays are changed with std::array.
  • #define directives are changed with constexpr values.
  • <filesystem> library is used for handing file/directory operations.