Add a utility to locate the root directory

[pepicrft]

Short description 📝

This PR adds a utility that given a directory, it traverses up the directories hierarchy to find the root of the project. It's considered the root of the project a directory that contains a Tuist/ directory, or where the git repository is defined.

The Tuist/ directory will contain the project description helpers, and in the future, some other global files that are accessible by any project.

Note: There are so many changes in the imports because I ran swiftformat.

[github-actions]

@pepibumur your pull request is missing a changelog!

[kwridan]

Nice 👍

There's an extra layer of caching that could be done but that could be a future optimisation if needed.

e.g.

• A
  • Tuist
  • B
    • C
    • D
    • E

Asking from C will traverse the file tree till A and cache:
"/A/B/C": "/A"

Asking from D, the cache doesn't have any entries for it, so will traverse again and update the cache
"/A/B/C": "/A"
"/A/B/D": "/A"

Seeing we've traversed via /A/B/ already, the cache could include that information to save a few lookups

Again this could be an enhancement later if needed 🙂