management: delete deprecated Command Interest

This commit deletes deprecated ControlCommand::makeCommandInterest method,
and edits a few documentation items and test cases where "command Interest"
is referred to.

This commit also removes a deprecated feature in ndn::nfd::Controller::start(
ControlParameter, CommandSuccessCallback, CommandFailCallback,
IdentityCertificate, time::milliseconds), where empty IdentityCertificate()
was previously acceptable as the fourth parameter to pick the default
certificate, but now it's interpreted as a certificate with empty Name.

refs #2008

Change-Id: I54c1b579cfb18c7662c20de40193be5543286841