Clarify blob handling.

In Python, the only semantic difference between `bytes` and `bytearray` data structures, is that the former are immutable and the latter are mutable. It is similar to the difference between tuples and lists.

However, in oscpy, bytes are treated as as an OSC-String and bytesarrays are treated as an OSC-Blob. They are treated differently as to whether they go through an encoding/decoding stage,

This distinction is not obvious nor intuitive.

Please consider treating `bytes` as OSC-Blobs, to make then consistent. Unicode strings should continue to be treated as strings and encoded/decoded.

Failing that please consider documenting this in the Gotcha section.

The issue names no files or tests. Start by locating oscpy's handling of bytes, bytearray, OSC-String, and OSC-Blob, then review the Gotcha documentation. Done means either bytes are treated as OSC-Blobs while Unicode strings retain encoding and decoding, or the distinction is explicitly documented there.

Written by the indexing model from the issue text.