## Link to GitHub Issue, if one exists
n/a
## Description of change
Change the usage pattern for Card Manager UI.
### Previous behavior
Previously, it was a list of cards that you select, and click a button
to insert as P1 or P2.
This is fine, but users got confused when they pressed `Insert Card`
overlay key and got a different card inserted, or when auto-insert
didn't work as expected.
Additionally, if you play a game without continue (IIDX/DDR for
example), then it's cumbersome to bring up the overlay and click on
insert card every time.
### New behavior
Insert Card overlay now lets you pick a card and *slot* it into P1 or P2
side.
From that point on, the slotted card number is used as the override,
replacing what was previously passed to `-card0` or `-card1`. This means
that `Insert Card` button and auto-insert will pick up the new card and
use that instead.
## Compiling
👍
## Testing
Tested 1p-only game (popn) and 2p games (DDR, IIDX).
bicarus-dev