[refactor] Refactor ticker to allow for variable number of character lists

[jinatonic]

This is continuation from #73 , sorry I don't know how PRs work on github.

This is a backward incompatible change in preparation for major release 2.

Breaking changes:

• Changed possible values for app:ticker_defaultCharacterList
• Completely recreated TickerUtils with new methods
• Removed the need to include TickerUtils.EMPTY_CHAR in every character list.
• setCharacterList now takes in a vararg of character lists. It’s also been renamed as setCharacterLists (plural).
• Supporting variable number of character lists have several advantages.

We don't have to specify the animation behavior from all possible characters.

Characters that do not exist in any character list can be treated differently by the animator. e.g. always prioritize preserving them via ACTION_SAME so they do not get animated. Can support more custom animation behavior since each character list gets priority over the previous.

e.g. [0, 1, 2] dictates animation behavior from 0 to 2, but what if I want a different behavior from 1 to 2? I can provide another character list that's something like [1, 3, 2].

Can support wrapping around behavior where 9 -> 0 properly wraps around the list rather than going all the way down. This is currently not possible because wrap-around in the current scenario would mean it would animate through all of the non-number characters (e.g. $).

closes #67

[jinatonic]

regarding your comment on String -> char[] conversion, i think it's fine because most likely when constructing these character lists they would have to do toCharArray anyway, and having the API accept string is definitely much easier to read.