Move helper disambiguation to a flag that is off by default

[mansona]

With #509 we introduced the ability to disambiguate helper calls by wrapping {{some-helper}} in round brackets like this {{(some-helper)}}. This helps in an embroider build but there is a bug somewhere in the stack with a classic build that causes this to fail at runtime.

We need to hide this functionality behind a flag so that people can opt-into it if it's something that they need/want i.e. if they are running embroider and wanting to turn on staticHelper and staticModifiers without turning on staticComponents 👍