We have the Text API, which is essentially a wrapper around a String and a
BytesReference and then we have 3 implementations depending on whether the
String view should be cached, the BytesReference view should be cached, or both
should be cached.
This commit merges everything into a single Text that is essentially the old
StringAndBytesText impl.
Long term we should look into whether this API has any performance benefit or
if we could just use plain strings. This would greatly simplify all our other
APIs that currently use Text.
6ea16671f4