Moved some files and functions

[tygoee]

Changes:

• Moved src/__main__.py to main.py to allow multiple subfolders in src/
• Moved a lot of functions in media.py, modloaders.py and other files
• Made src/runner.py the "main" file, as it invokes all functions
• Changed all class methods in media.py to instance methods which are more fitting

[tygoee]

Added last 2 commits: there was an unintended dummy confirmation prompt and while testing a flake8 error saying the import size was being shadowed by a loop variable