[Feature]: View bank anywhere (without interacting with bank teller)

[Racksoup]

Describe the feature

I'd love if BetterBags was able to show your bank contents at any time.

Describe the implementation

same exact layout as the bank/bag has currently. save bank items so they can be viewed later. a small button at the top of the betterbags bag window to show/hide the bank view

[SpareSimian]

Part of issue #26 and issue #453