Closes#766
- changes the on-disk representation from % to a multiplier,
eg 250 -> 2.5, as this is consistent with the other options
- resets deck configs at or below 1.3 to 2.5
- for any cards that were using a reset deck config, reset their
current factor if it's at or below 2.0x. The cutoff is arbitrary,
and just intended to make sure we catch cards the user has rated
Easy on multiple times. The existing due dates are left alone.
- tag list stored in a separate DB table
- non-wildcard searches now do full unicode case folding
(eg tag:masse matches 'Maße')
- wildcard matches do simple unicode case folding
- some functions haven't been updated yet, so ascii folding will
continue to be used in some operations
- on collection load, the schema is upgraded to 12
- on collection close, the changes are reversed so older clients
can continue to open the collection
- in the future, we could potentially skip the reversal except
when exporting/doing a full sync
- the same approach should work for decks, note types and tags in the
future too
- the deck list code needs updating to cache the deck confs for the
life of the call
