bluArrayStrings Improvements

* Renamed from bluArrayString to bluArrayStrings for clarity (there may
be other types in the future)
* Added a `CaseSensitive` property
* Added an `Index` property to retrieve the Index number given a search
String
* Made 1-based to simply internals, as well as allow for a zero return
value for the `Index` property to signal "not found"
bluArrayStrings: `Index` property wasn't working