feature: tell a hibernating server about its match on its ping

[lukepolo]

• a hibernating CS2 server does not answer RCON at all, so get_match never reaches it
• the server ping now replies { get_match }: true when the match the plugin says it has loaded is not the one it has been given
• a plugin that reports hibernating=true is remembered for 45s, and a failed RCON connect to it is not recorded as a fault or alerted on
• older plugins send neither parameter and are unaffected

Built on #513, so merge that first.

Draft: goes with 5stackgg/game-server#214, to be tested together on a dev server.

[lukepolo]

Not needed. A hibernating CS2 server does answer RCON: a corrected test logged in and read a cvar from one without waking it, so get_match reaches it as it does today. The earlier "no reply" came from a test that waited for more bytes than the server sends. The auth fix is in #513 on its own.