fixed eavesdrop channel management via ESL

[sergey-safarov]

The current switch_ivr_eavesdrop_session implementation does not call switch_ivr_parse_all_events and leads to the case when executing eavesdrop application blocks any command execution sent via ESL.

This PR fix this.
I have tested locally.

[signalwire-ci]

Unit-tests failed: https://public-artifacts.signalwire.cloud/drone/signalwire/freeswitch/1707/artifacts.html

[sergey-safarov]

The issue can be reproduced using this test script

#!/bin/perl

use ESL;

my $uuid = shift;
my $args = join(" ", @ARGV);

my $con = new ESL::ESLconnection("127.0.0.1", "8021", "ClueCon");

my $e = $con->execute('info', '', $uuid);

need to call the script using commands like

./test.pl a0aac03e-0956-4adc-82b5-08a19b6155be

Without this patch, the channel variables will not printed with the active eavesdrop application.
With this patch channel variables will be printed into the FreeSwitch log.