Refactored error system and abstracted functions into own file

[stifskere]

Changes

This PR contains a few non breaking changes, these are most likely code quality changes and how errors are handled, which basically reduces to

• Remove unused imports.
• Install and implement thiserror for every function.
• Delegated error display to the main function removing usage of expect.
• Improved code readability by adding line breaks between expressions.
• Changed moves to references in most places.
• Changed implementations and respective function names.

Now all the modified functions return their respective Result<_, Err> with their own implementation of thiserror.

[stifskere]

I don't really understand how the format is implemented, and why it wouldn't be -o like traditional C compilers, there are no actual expectancy tests so I believe everything works correctly from my tests, it works as before, but the --format argument is quite confusing.

[SergioRibera]

Small details that can improve the code a little, but otherwise I like it a lot.