TagInput should have a string-only variant with simpler prop types

Working with onRemove: (value: React.ReactNode, index: number) is inconvenient under TypeScript's strict compiler options. Even when the values prop is string[], you are either forced to type cast the removed value to string or use the index parameter to index into your values array. We should make the simple case easier to work with, either with a new component API or changing the existing component to be parameterized by its data type <T>.