game specifc joystick port selection has to be persisted

[mithrendal]

when the user selects a joystick port in a game lets say

pacman -> port 2
choplifter ->port 1

then vc64web has to remember that selection just like it currently does remember the action buttons for a specific game

when choosing a joystick port that selection has to be saved under the app / game title key in the indexedDB for later retrieval

then on another rainy day the user selects a snapshot of pacman
Result: it loads the snapshot and sets the joystick selection automatically to 2

the user selects a snapshot of pacman
Result: it loads the snapshot and sets the joystick selection automatically to 1

OMG: when this is done should we relabel virtualc64web to vc64AE (ArcadeEdition) then 🤔 ? ... better not ... Arcade sounds not too serious ... (Are we serious ?🕺🏾 Yes we are! 😎)