refactor!: drop CT_ prefix from ContentFormat constants, change type to int (uint16)

[szysas]

The prefix carried no information once the class name says it: ContentFormat.CT_APPLICATION_JSON stutters, ContentFormat.APPLICATION_JSON does not.

Fix three long-standing defects in their names:

CT_APPLICATION_LINK__FORMAT -> APPLICATION_LINK_FORMAT double underscore
CT_APPLICATION_OCTET__STREAM -> APPLICATION_OCTET_STREAM double underscore
CT_APPLICATION_CODE_* -> APPLICATION_COSE_* "CODE" is a typo for COSE

Pure rename, no behaviour or type change.

Content-Format is a uint16 in RFC 7252, but it was modelled as a signed short. Parsing did setContentFormat((short) data.toLong()), so any content format >= 32768 -- the whole upper half of the IANA registry, including the 65000+ experimental range -- was truncated to a negative number and re-serialized wrong. A round trip of 32768 produced 0.

Retype content format to int/Integer across the constants, header options, builders and factories. The parser assigns the field directly rather than going through the setter, so a malformed peer sending a value outside the uint16 range cannot throw out of the deserializer.

Fix the neighbouring types that cannot represent their domains either: the option-number constants (byte -> int, option numbers are uint), DEFAULT_MAX_AGE (short -> long, matching the Long maxAge field), CoapConstants.MAX_RETRANSMIT (Short -> int) and LinkFormat content type (Short -> Integer). Collapse the setAccept(short) / setAccept(Integer) overload trap into a single method.

BREAKING CHANGE: ContentFormat constants have lost the CT_ prefix, and the misspelled CT_APPLICATION_CODE_*, CT_APPLICATION_LINK__FORMAT and CT_APPLICATION_OCTET__STREAM names are corrected. Content format is Integer/int instead of Short/short across header options, builders and factories;