Add toString to Kvp
Add ElementType enum (KEY, VALUE)
Add Option enum describing how a key or value may be optionally mutation upon construction of Kvp
Differentiate between Kvp and SecureKvp, where key may be recognized to be protected, thus masking the value assigned to it
Add tests for Kvp and SecureKvp
Add functionality to mutate K and V in a flexible way. More to go, this is a first step