DDSSEC12 — Using string literals as binary_property values inside Handshake Tokens

In the definition of the various Handshake Tokens, certain property values are specified with literal strings in the spec (such as "RSASSA-PSA-SHA256"). Since these are inserted into binary_properties, the spec should describe the encoding: is there a length prefix (like CDR string?), is there a trailing nul (like CDR string?), assume the encoding is ASCII but it would be good to specify this.