Move ensureCapacity to grouped state interface
Add support for more opcodes
Add typed ret() function
Add ensureCapacity(capacity, defaultValue) to all big array classes
Add bytecode generation for aggregation state classes
Convert BooleanMin and Max to use new aggregation base class
Convert COUNT_IF to use new aggregation base class
Use LongState instead of NullableLongState for COUNT
Convert variance aggregation to use new aggregation base class
Add support for Slice in state compiler
Convert varchar min/max aggregations to use new aggregation base class
Remove ensureCapacity(long, type) from big arrays

Big arrays now store the initial value set in the constructor, and use
that value when ensureCapacity is called