Improve Homebrew Store installation workflow

[EduDicaseGameplay]

Summary

This PR improves the Homebrew Store installation workflow by making the installation device selection more flexible and user-friendly.

Background

While testing the Homebrew Store, I noticed that in some setups the installer would always use Hdd1: as the installation destination, even when another storage device was intended to be used.

This caused installation failures in my console and in some other setups from members of my Xbox 360 community, especially for users who don't have an internal HDD or who prefer installing content to USB storage.

I also noticed that some users solved this by manually changing the homebrewstore.conf file. Community guides have provided preconfigured versions of this file for Usb0: or Usb1: installations, which works as a solution but requires manual changes depending on each user's configuration.

Changes

• Added a storage device selection option before starting the installation process.
• Allows users to choose the desired installation destination instead of relying only on the default Hdd1: path.
• Reduces the need for manual edits or replacing the homebrewstore.conf file for different storage configurations.
• Improved menu flow and usability.
• Refactored parts of the code to support the new workflow while keeping the original functionality.

Benefits

• Provides better flexibility for different Xbox 360 storage setups.
• Makes installation easier for users with different configurations.
• Helps avoid installation failures caused by incorrect default paths.
• Keeps compatibility with the original Homebrew Store behavior.

Testing

Tested on Aurora 0.7b2 with different storage configurations, including USB-based setups.