Wrap arg in parens when needed when adding new keyword

[brianrourkeboll]

• Update the "add new keyword" code fix to wrap the constructor argument in parentheses when needed, so that applying the fix does not cause Inconsistent handling of arguments for disposable types dotnet/fsharp#15622.

This change incidentally also prevents the code fix from suggesting a "fix" that would be invalid in various scenarios,¹ e.g.:

(Disposable) arg // Formerly suggested `(new Disposable) arg`, now suggests nothing.

xs |> List.map Disposable // Formerly suggested `xs |> List.map new Disposable`, now suggests nothing.

Footnotes

1. We could in theory update the code fix to suggest new (Disposable)(arg) (or even new Disposable(arg)), xs |> List.map (fun x -> new Disposable(x)), etc., for such scenarios, but I considered that out of scope for this PR—and perhaps altogether, since transformations like xs |> List.map (fun x -> new Disposable(x)) also may not be valid, depending on the type of the constructor argument! For example, if xs is a unit list, then transforming xs |> List.map Disposable to xs |> List.map (fun x -> new Disposable(x)) is not valid. ↩

[TheAngryByrd]

Thank you!!