kigen: Go 1.18+ Generics Libraries, for GoKi framework

This collection of Generics libraries takes advantage of the new generic type parameters introduced in Go 1.18.

ordmap: ordered map

Implements an ordered map that retains the order of items added to a slice, while also providing fast key-based map lookup of items.

dedupe: deduplicate (uniquify) any slice with comparable elements

Implements a de-duplication function for any comparable slice type, efficiently using a map to check for duplicates. The original order of items is preserved.