Improve UI

[zoeyjodon]

Overview

Basic UI improvements, including:

• Preventing the app from exiting after every command
• Allowing users to select the streaming host without the config file
• Allowing users to select the streaming app without the config file
• Allowing users to exit the app via the home button

Changelog

• Moves main logic for the 3DS into a separate file
• Creates subdir for 3DS specific code
• Adds logic for storing/listing paired host addresses in memory
• Modifies the sample config file with improved settings
• Reverts logic in main.c and guards it from 3DS builds
• Adds calls to aptMainLoop in all main processes to allow exiting to the home menu
• Adds common "prompt for input" function to generate user prompts and receive feedback
• Moves main logic under a while loop to prevent app exit after each command
• Replaces "list" command with a prompt during streaming setup where users can select the app they want to run
• Simplifies initialization status checks
• Adds user prompt for setting the host address in-app