Using operation from proposal provider should print brackets

[tkutz]

When selecting an operation from proposal provider, no brackets are printed after the operation name. In case the operation has at least one parameter, we should print the brackets and put the cursor between the brackets.

[BeckmaR]

I would say the brackets / parantheses should always be printed, although it works without them if there are no arguments - but that looks pretty confusing.

[terfloth]

We explicitly decided to make brackets optional for no arg ops. So creating brackets for the case operations require parameters is valid.