fix missing inlines in various headers and incorrect pointers in 'from_variable'

[thiago-carneiro]

This pull request resolves two key issues:

• Missing inline Specifiers:
  Several standalone function definitions in header files were missing the inline specifier. Since these functions are not member functions defined inside a class body, nor constexpr or template functions, they are not automatically given inline linkage by the compiler. Adding the inline specifier prevents multiple definition errors when these headers are included in multiple translation units.

• Incorrect Pointer Usage in from_variable:
  The from_variable function previously accessed array data using .data(), which could result in incorrect memory offsets when handling sliced variables with non-zero origins. This has been corrected to use byte_strided_origin_pointer().get(), ensuring proper handling of array origins and memory layout.

[BrianMichell]

Proper clang formatting was holding the CI/CD pipeline back. Fixed.