Use f-strings
Avoid unnecessary casts to str()bool()int()
Ensure file closure
Merge nested ifs
Simplify for-assigns-appends with comprehensions and internal functions
Avoid shadowing internal function names
Initialize variables
Return value directly instead of assign then return
Make some methods static
* screen/printer_select/splash_screen: Updates to allow changing between moonraker instances
* Updates to multiple printers
* settings: Display printer endpoints
* Update macros to be on a per-printer basis
* files: Changes to clear out file cache on printer switch
* job_status: Redo page for action bar
* splash_screen: Change icon
* websocket: Actually close the websocket
* printer: Fix error case
* splash_screen: show buttons update
* readme update
