Correct query RangeKeyCondition filtering for a numeric Range Key.

Also provided "cloned" test methods within AlternatorQueryTest.java to test the .query method against a table with a numeric range key.  The prior test methods that test against a string range key still exist.

Note that this implementation compares numeric values _after_ converting them to strings.
This 11 = "11" and is LT (or LE) 2 = "2".  Similarly, 1, 11, 123 all BEGINS_WITH 1. 1, 51, and 313 all CONTAINS 1.