Add query support for indexed artithmetic functions

[alecgrieser]

Using FunctionKeyExpressions, we can support indexes on things like "a + b" or "a & b" (bitwise and). We should provide those as some built-in queryable function key expressions that allows us to define queryable indexes on the function results.

To make it work with Cascades, we should ensure that we have appropriate function values, and that we can match those during planning. We already have a few built-in function Values for things like addition, though there are a few others that we'll need to add for things like bitwise operators.