smb/dce-rpc: Cleanup DCE-RPC analyzers when fid is closed and limit them

This patch does two things:

1) For SMB close requests, tear down any associated DCE-RPC
   analyzer if one exists.

2) Protect from fid_to_analyzer_map growing unbounded by introducing a
   new SMB::max_dce_rpc_analyzers limit and forcefully wipe the
   analyzers if exceeded. Propagate this to script land as event
   smb_discarded_dce_rpc_analyzers() for additional cleanup.

This is mostly to fix how the binpac SMB analyzer tracks individual
DCE-RPC analyzers per open fid. Connections that re-open the same or
different pipe may currently allocate unbounded number of analyzers.

Closes #3145.

scripts/base/frameworks/notice/weird.zeek

@@ -211,6 +211,7 @@ export {
 		["spontaneous_RST"]                     = ACTION_IGNORE,
 		["SMB_parsing_error"]                   = ACTION_LOG,
 		["SMB_discarded_messages_state"]        = ACTION_LOG,
+		["SMB_discarded_dce_rpc_analyzers"]     = ACTION_LOG,
 		["no_smb_session_using_parsesambamsg"]  = ACTION_LOG,
 		["smb_andx_command_failed_to_parse"]    = ACTION_LOG,
 		["smb_tree_connect_andx_response_without_tree"] = ACTION_LOG_PER_CONN,