captive-portal: adjust timeout to handle alarms correctly

[nqb]

Describe the bug
I'm pasting here what @julsemaan described regarding that issue:

The code we have that sets an alarm:

packetfence/html/captive-portal/lib/captiveportal.pm

Lines 52 to 73 in dcad596

	around 'handle_request' => sub {
	my ($orig, $self, @args) = @_;
	my @res;
	# Request timeout handling
	eval {
	local $SIG{ALRM} = sub {
	my ($pkg, $file, $line) = caller(0);
	(undef, undef, undef, my $func) = caller(2);
	die "Timeout reached at package:$pkg, file:$file, line:$line func:$func";
	};
	alarm $Config{captive_portal}{request_timeout};
	eval {
	@res = $self->$orig(@args);
	};
	alarm 0;
	die $@ if($@);
	};
	alarm 0;
	die $@ if($@);
	return @res;
	};

This line is problematic: https://github.com/inverse-inc/packetfence/blob/devel/conf/httpd.conf.d/httpd.portal.tt.example#L111
After 5 seconds, the request can timeout in Apache mod_perl but the alarm is still setup in Catalyst. 10 seconds after, the alarm is fired in Catalyst but the code to catch it isn't active anymore (killed after the 5 seconds) and the alarm bubbles up to the parent process

We need to make the Apache timeout a value of captive_portal.request_timeout + 5 seconds so that the Catalyst code always has a chance to run before Apache kills the process

Additional context
This is what I see in httpd.portal-error when this issue occured:

Jun 20 16:32:54 packetfence httpd_portal_err: [Mon Jun 20 16:32:54.446558 2022] [perl:error] [pid 22162] [client 127.0.0.1:55382] Apache2::RequestIO::read: (70007) The timeout specified has expired at (eval 4288) line 5
Jun 20 16:32:54 packetfence httpd_portal_err: [Mon Jun 20 16:32:54.509008 2022] [perl:error] [pid 21225] [client 127.0.0.1:55384] Apache2::RequestIO::read: (70007) The timeout specified has expired at (eval 4678) line 5
Jun 20 16:32:54 packetfence httpd_portal_err: [Mon Jun 20 16:32:54.612337 2022] [perl:error] [pid 21759] [client 127.0.0.1:55386] Apache2::RequestIO::read: (70007) The timeout specified has expired at (eval 5046) line 5
[..]
Jun 20 16:33:05 packetfence httpd_portal_err: [Mon Jun 20 16:33:05.375322 2022] [core:notice] [pid 10615] AH00052: child pid 22162 exit signal Alarm clock (14)

Results: httpd.portal is not working anymore and need to be restarted.