Support BigNumber Query Options

[dOrgJelli]

Support BigNumber query option types for EntityClass.search(...) methods. This would, for example, enable querying all members who have "greater than 400 reputation".

This can be done by creating a new type that wraps the number property and the corresponding suffix:

interface BigNumberQuery {
  propertyName: string
  propertyValue: number
  suffix: "gt" | "lt" | "gte" | "lte"
}

[jellegerbrandy]

Looks like a good idea.
Afaics, to "supporting" all these options is simply a matter of allowing these values as keys in IXXXQueryOptions.

(I do not how you want to do the "BigNumberQuery" type)

[jellegerbrandy]

(before #217 was resolved we were actually "supporting" all these query options)

[jellegerbrandy]

I re-insted the [id: string]: any in the query types, so we can pass any argument, as a quick but flexible solution - seemed better then copying over all the types from the graph...