refactor(solc): remappings detection rewrite

[mattsse]

Motivation

Fix #728

Solution

New approach to detect remappings for a variety of patterns

• keep track of a valid window while recursively scanning dirs for candidates. A new window, is opened after a new lib dir was found (lib, node_modules): lib/solmate/lib/weird-erc20, contains 2 windows (solmate, weird-erc20). this also allows us to merge multiple candidates in the same window like in oz/{auth, tokens,..}/contracts auth and tokens are contained in the same window oz and should be merged to oz

This is a better-structured version, which also handles all edge cases we're currently aware of, once we discover new ones, they can be easily added

Integration tests pass on foundry foundry-rs/foundry#305

PR Checklist

• Added Tests
• Added Documentation
• Updated the changelog