meta-info: deprecate MetaInfo::TYPE_* constants

The following items are deprecated:

* tlv::ContentType_Default
* MetaInfo::TYPE_DEFAULT
* MetaInfo::TYPE_BLOB
* MetaInfo::TYPE_LINK
* MetaInfo::TYPE_KEY
* MetaInfo::TYPE_NACK

refs #2128

Change-Id: I01f0aa0dd27d32a18a9fff79401b5784d9ddcb10