Add KVArrayValue and KVBinaryBlob value types

[xPaw]

KVArrayValue is List<KVValue>, and KVBinaryBlob is byte[] because List<byte> would be silly.

@yaakov-h this is to be used by kv3 pls review. api surface generator is failing for some reason.

[yaakov-h]

Could KVBinaryBlob be a Memory<byte> or at least ArraySegment<byte> so that callers can be more efficient than allocating exact-size managed arrays?

I'm also seeing a lot of overlap between KVArrayValue and KVCollectionValue, is there any way we could merge them, or is that more complexity?

[yaakov-h]

The test failure seems to be a bug / unforeseen edge case in the test - a method has the same name as a method in the base class, but the base class has multiple methods by the same name.

[xPaw]

I think most of the overlap is just unimplemented IConvertible region?

Could KVBinaryBlob be a Memory or at least ArraySegment so that callers can be more efficient than allocating exact-size managed arrays?

The caller is the deserializer, so it's gonna allocate the byte array regardless (but in binary deserialization this could be a memory view yeah -- although this has some implications on the ownership of the byte array)

[xPaw]

I've fixed it to not crash when base type has multiple overloads. Maybe there's some library we could use that does correct api surface dumps for us?