As a policy writer I want to be able to get the values for variables that are found by variablesmatching

Today getting the values out of variables based on the return of variablesmatching is tricky and error prone.

Here is an example based on data containers
https://gist.github.com/neilhwatson/da3176a83d397600bfca

Trying to construct a classic array where the index is the value of the found variables results in a programming error (noted in #7254

<pre>
body common control
{
bundlesequence =>

;
}
bundle agent any
{
vars:
"open_ports" slist =>

;
}
bundle agent apache
{
vars:
"open_ports" slist =>

;
}
bundle agent iptables
{
vars:
"port_list" slist => variablesmatching(".*open_ports");

"port_array[$($(port_list))]" string => "1";
}
</pre>

Getting the values of the variables that you found is a logical next step and I think we should make it easier.

Perhaps a new function to getvaluesfromvariablesmatching() that returns a list of all values.

Additionally being able to getvalues/indices from a list of lists could ease this.