imap: Added secured and ssl_secured flags

This adds two new boolean fields: 'secured', and 'ssl_secured' to the
imap client structure, these reflect the values of conn_secured and
conn_ssl_secured respectively.

This is a prerequisite to integrating the imap_capability_list APIs into
imap because imap needs to distinguish between secured/tls/non-secured
connections when determining whether conditional capabilities should be
displayed or not.

Author: shaun-a-johnson

src/imap/imap-client.h

@@ -233,6 +233,8 @@ struct client {
 	bool mailbox_examined:1;
 	bool anvil_sent:1;
 	bool tls_compression:1;
+	bool secured:1;
+	bool ssl_secured:1;
 	bool input_skip_line:1; /* skip all the data until we've
 					   found a new line */
 	bool modseqs_sent_since_sync:1;

src/imap/main.c

@@ -285,6 +285,8 @@ int client_create_from_input(const struct mail_storage_service_input *input,
 			       event, mail_user, user, imap_set, smtp_set);
 	client->userdb_fields = input->userdb_fields == NULL ? NULL :
 		p_strarray_dup(client->pool, input->userdb_fields);
+	client->secured = input->conn_secured;
+	client->ssl_secured = input->conn_ssl_secured;
 	event_unref(&event);
 	*client_r = client;
 	return 0;