WT-10740 and its follow up WT-11484 highlight that how WT casts can cause issues with modern compilers. Some of this is how the API works so we can't change that, but other parts, e.g. with the WT_CELL_UNPACK* structs, is internal and we should review the strategy to be compliant with the compiler and be easy to reason about the code.

The outcome of this ticket is to identify a strategy for what is good / required / bad casting with modern C and then recommend steps forward to achieve that.