multiple fixes

[JanDeDobbeleer]

• fix(git): do not convert path when using native_fallback in WSL
• feat(shell): allow user to specify the cache path with OMP_CACHE_DIR

Prerequisites

• I have read and understood the contributing guide.
• The commit message follows the conventional commits guidelines.
• Tests for the changes have been added (for bug fixes / features).
• Docs have been added/updated (for bug fixes / features).

Description

🤖 Generated by Copilot at 0237901

This pull request enhances the scm segment for WSL users and adds a new option to customize the cache path for oh-my-posh. It also improves the code style and documentation of some files.

How

🤖 Generated by Copilot at 0237901

• Add OMP_CACHE_DIR environment variable to set cache path for oh-my-posh (link)
• Add nativeFallback field to scm type to use native command as fallback when command.exe version is not available or fails (link)
• Skip path conversion when nativeFallback is true in convertToWindowsPath function (link)
• Set nativeFallback to true when native command is used as fallback in hasCommand function (link)
• Explain logic of hasCommand function with comment and add blank lines for readability (link, link)
• Add blank lines for readability in branchName function (link)