Add methods to detect whether underlying format can support read/write binary natively

[cowtowncoder]

Some formats can write binary data "natively", without using encodings like Base64: for example Smile and Avro formats. Others require encoding.
But while parser and generator implementations have knowledge of this, databind does not know whether this is true.

When writing explicitly binary data, knowledge is not all that important: generator and parser can handle it transparently.
But there are types like java.util.UUID, where ability for use of direct binary representation would be useful (16 bytes raw, vs 36 character textual) -- yet use of base64-encoding may or may not make sense: 24 bytes base64-encoding is more compact, but less readable.

So: let's add capability detection methods to let databinding choose binary in cases where native support exists.