feat(huff_core): Remapping Import Resolution

[refcell]

Overview

Tackles #187

Adds remapping support for import resolutions. So a remapping in a foundry.toml can be supported when compiling huff contracts. For example, a remapping for huffmate like huffmate/=lib/huffmate/src/ located in a foundry.toml file can be successfully parsed by the huff compiler. This allows you to import huffmate contracts inside a huff contract using foundry.toml remappings (WLOG)

Note: This PR rips out file path validation logic in the parser since files are validated and fully flattened at the compiler top-level.

[refcell]

RFC @clabby