Add the list functions that will be used for memory pools.

Instead of using macros, use iterators built-in on each list for
filtering and traversing.

Add some missing parts.

Remove symlinks and make codebase use common modules instead.

Ensure mounts are configurable.

Split callback logic into several functions.

Update initialization method.

Allow current item pointer to have custom type.

Change the pool list initializations.

Add memory and data-related implementations for handling game data.

Properly mock video function dependencies.

Correctly dereference pointers.

Update input tests.

Declare memory before processing.

Declare variables early on.

Add geometry methods for point, vector, and rectangle.