Add methods to KiwiResources to validate parameters from MultivaluedMaps

[sleberknight]

Add new parameter validation methods in KiwiResources that accept MultivaluedMap. Even though MultivaluedMap extends Map we have run into problems in which the method resolution picks the "wrong" method. See #571 for details, and specifically the @implNote in the Javadocs in WebTargetHelper for why having separate methods from the existing validateXxxParameter methods is the right thing to do (despite it being annoying).

So, in addition to the validateIntParameter and validateLongParameter methods which take a Map<String, V> (or will, once #603 is implemented), these new methods will specifically accept MultivaluedMap<String, V> where V is a type parameter.

Since MultivaluedMap by definition permits more than one value for a key, we will want to have separate methods to handle the cases when you know you only want one parameter (e.g. /url?n=42), and when it's OK to have one or more (e.g. /url?n=42&n=84). So, the new method signatures might look like:

// Validates there is exactly one parameter with the given name
// whose type is an int, and return as an int
public static <V> int validateOneIntParameter(MultivaluedMap<String, V> parameters, String parameterName)

// Validate that there are one or more parameters with the given name
// whose types are all ints, and return as a list of Integer
public static <V> List<Integer> validateManyIntParameters(MultivaluedMap<String, V> parameters, String parameterName)

// Validates there is exactly one parameter with the given name
// whose type is an long, and return as a long
public static <V> long validateOneLongParameter(MultivaluedMap<String, V> parameters, String parameterName)

// Validate that there are one or more parameters with the given name
// whose types are all longs, and return as a list of Long
public static <V> List<Long> validateManyLongParameters(MultivaluedMap<String, V> parameters, String parameterName)

One question is whether the validateOne methods should throw an exception if there is more than one parameter with the given name? Or, should there be separate validateExactlyOne methods in addition which would be the ones that throw exceptions, whereas the regular validateOne methods just grab the first query parameter with the given name?

[sleberknight]

Also see https://gist.github.com/sleberknight/b1a47505815069125e03431163ad5b44