Remove duplicate aliases

[timsaucer]

Describe the bug

We have places in the rust code where aliases are defined but not used now that we have the python wrappers. For example, the function array_append has the following aliases defined in functions.rs: array_push_back, list_append, and list_push_back. These are not being used in the python wrappers, which do their aliases themselves.

We should remove these pieces of duplicate code.

To Reproduce
This doesn't cause any degraded performance except bloat of the distributed files.

Expected behavior
We should not have duplicate aliases.

Additional context