Code Cleanup

This PR contains numerous code cleanup commits. I wanted to make these before I make some more intensive changes to avoid the issues I was running into understanding the existing code and some code duplication. A summary of the changes is:

1. Moved utils out of a wildcard import to avoid warnings on utils.py imports overriding default.py imports.
2. Unified common code in 5 functions to set section parameters (i.e. GetFilteredResults, all the Searches, Browse Favorites, etc.)
3. Unified code to create playable items used in 5 functions (i.e. GetFilteredResults, all the Searches, Browse Favorites, etc.)
4. Fixed a few places where non-existent functions were called (e.g. os.path.mkdir doesn't exist)
5. Removed the get_by_letter function since it was no longer used.
6. Converted spaces to tabs where inconsistent indentation was being used in some cases.
7. Removed the fix_strms code since it 1) was for an older version 2) update_subscription will now do it automatically 3) It was causing some users to get errors during upgrades.