[client,management] Feature/client service expose (#5411)

CLI: new expose command to publish a local port with flags for PIN, password, user groups, custom domain, name prefix and protocol (HTTP default).
Management/API: create/renew/stop expose sessions (streamed status), automatic naming/domain, TTL renewals, background expiration, new management RPCs and client methods.
UI/API: account settings now include peer_expose_enabled and peer_expose_groups; new activity codes for peer expose events.

management/server/store/sql_store.go

@@ -2114,7 +2114,8 @@ func (s *SqlStore) getServices(ctx context.Context, accountID string) ([]*revers
 			s.Meta.CreatedAt = createdAt.Time
 		}
 		if certIssuedAt.Valid {
-			s.Meta.CertificateIssuedAt = certIssuedAt.Time
+			t := certIssuedAt.Time
+			s.Meta.CertificateIssuedAt = &t
 		}
 		if status.Valid {
 			s.Meta.Status = status.String