This allows for pasting in comma separated lists that will validate
pills on paste, along with creating an API for inserting many pills.
This now allows in the `input_pill.pill.append` a comma separated list
that will then call the `insertManyPills` method that will break up the
input and then call `append`.
The function should execute initially and return a function, not
be a function that when executed returns another function. This
fixes an existing bug.
Some of the calls in our codebase will call for the `.keys()` method a
lot, so this caches the results and returns them rather than mapping
the array if it knows the state to be the same as before.
If a user clicks on the pill container and not directly on a pill
or on an "x" inside of a pill, it should be presumed they are
trying to input new text. This effectively makes the whole non-pill
section an input bar.