need rule engine selection option when submitting rule text to run

[trel]

Since 4.2.0 introduces a pluggable rule engine framework - there can be more than one rule engine available to the server.

irule has grown the ability to specify the rule engine instance that should run the submitted rule text. By default, the rule engine used is the first in the rule_engines JSON array from the connected server's server_config.json file.

The cloud browser needs a similar capability. Perhaps a dropdown with the default selected based on the same criteria (first on the connected server).