While investigating #2247 I used a parameter to create a stable password for a RabbitMQ resource, only to find that the password I'd generated contained a character that broke the connection string. RabbitMQ connection strings are actually URIs, so if the username or password contains restricted characters (e.g. @) then the RabbitMQ client fails due to the URI being invalid.

I updated ReferenceExpression to support custom value escaping and a convenience method for getting a URI escaped version of an existing ReferenceExpression and that solves the issue for runtime, but this issue will occur during manifest processing too. Resolving that is a much bigger challenge that will need some thought.