Add no-unnecessary-callback-wrapper rule

[andy-hanson]

PR checklist

• Addresses an existing issue: #0000
• New feature, bugfix, or enhancement
  • Includes tests
• Documentation update

Overview of change:

Added the no-redundant-callback rule, which warns on x => f(x) (prefer just f).

CHANGELOG.md entry:

[new-rule] no-unnecessary-callback-wrapper

[ajafff]

As always, I need to bikeshed about the rule name.
"redundant callback" means this to me:

function foo(cb: () => void) {
    cb();
    cb();
    ~~~~~ [redundant callback]
}

I'd rather change the name to something like no-unnecessary-wrapper(-function)?

[IllusionMH]

Or no-unnecessary-callback-wrapper

[nchen63]

looks good. Thanks

[adidahiya]

👍 let's include this in tslint:latest