oLIB and MLy VOEvents do not have central_frequency and duration values

The content of VO alert voevents are missing p_central_freq p_duration for MLy, and p_duration for oLIB. Fir oLIB is still present the "fluency" that the collaboration has decided not ti distribute.

Related issue: emfollow/gwcelery#594 (closed)

The code should be changed (my guess to):

        elif isinstance(event, LalInferenceBurstEvent):
            p_freq = vp.Param(
                "frequency",
                value=float(event.frequency_mean),
                ucd="gw.frequency",
                unit="Hz",
                ac=True,
            )
            p_freq.Description = "Mean frequency of GW burst signal"
            v.What.append(p_freq)

            # Calculate the fluence. 
            # From Min-A Cho: fluence = pi*(c**3)*(freq**2)*(hrss_max**2)*(10**3)/(4*G)
            # Note that hrss here actually has units of s^(-1/2)
            # XXX obviously need to refactor here.
            # try:
            #     fluence = pi * pow(c,3) * pow(event.frequency,2) 
            #     fluence = fluence * pow(event.hrss,2)
            #     fluence = fluence / (4.0*G)
            # 
            #     p_fluence = vp.Param(
            #         "Fluence",
            #         value=fluence,
            #         ucd="gw.fluence",
            #        unit="erg/cm^2",
            #         ac=True
            #     )
            #     p_fluence.Description = "Estimated fluence of GW burst signal"
            #     v.What.append(p_fluence)
            ### Duration
            p_duration = vp.Param(
                "Duration",
                value=float(event.duration),
                unit="s",
                ucd="time.duration",
                ac=True,
            )
            p_duration.Description = "Measured duration of GW burst signal"
            v.What.append(p_duration)
        elif isinstance(event, MLyBurstEvent):
            p_central_freq = vp.Param(
                "CentralFreq",
                value=float(event.central_freq),
                ucd="gw.frequency",
                unit="Hz",
                ac=True,
            )
            p_central_freq.Description = \
                "Central frequency of GW burst signal"
            v.What.append(p_central_freq)

            ### Duration
            duration = event.quality_mean / (2 * np.pi * event.frequency_mean)
            p_duration = vp.Param(
                "Duration",
                value=float(duration),
                unit="s",
                ucd="time.duration",
                ac=True,
            )
            p_duration.Description = "Measured duration of GW burst signal"
            v.What.append(p_duration)
        except Exception as e:
            logger.exception(e)