Issue #135 describes adding a total message length field to the DIDComm header as a way of enabling agents to specify the size of messages they are willing to receive. This PR implements this capability without modifying the message header. Instead, this PR accomplishes the same goal by adding a new Agent Capability Disclosure section to the Transports page, which introduces a method of using the Discover Features Protocol to enable agents to query for and disclose the maximum message length that they are willing to accept.
Issue #135 describes adding a total message length field to the DIDComm header as a way of enabling agents to specify the size of messages they are willing to receive. This PR implements this capability without modifying the message header. Instead, this PR accomplishes the same goal by adding a new Agent Capability Disclosure section to the Transports page, which introduces a method of using the Discover Features Protocol to enable agents to query for and disclose the maximum message length that they are willing to accept.