Use modern C++ casts instead of current C-style casting approaches

### Description

Update various API implementations that use c-style pointer casting and other c-style approaches to use modern C++ casts.

### Is this a breaking change?

The function signatures would remain unchanged
The behavior of the functions would be identical
User code that calls these functions wouldn't need any modifications

### Additional information

Modernizes the code base. Compilers will optimize these the same, but coding standards favor using C++ cast in C++ code.

Start by locating the API implementations that use C-style pointer casts or other C-style casting approaches. Replace the relevant casts with modern C++ casts while preserving function signatures and behavior, then verify that the implementations still build and behave identically.

Written by the indexing model from the issue text.