Add configuration to no-inferrable-types to ignore annotated function parameters

[Arnavion]

The no-inferrable-types currently complains if a function parameter has both a type annotation and a default value.

TypeScript code being linted

function foo(bar: number = 0) { }

with tslint.json:

{
    "rules: {
        "no-inferrable-types": true
    }
}

Actual behavior

LHS type (number) inferred by RHS expression, remove type annotation

---

It would be nice if the rule had a configuration to skip function parameters. I prefer documenting the types of function parameters explicitly regardless of whether they're default-initialized or not.

[rrogowski]

I believe this was addressed by #1190.

Running tslint on the above code example with the following rules gives no lint error.

{
  "rules": {
    "no-inferrable-types": [ true, "ignore-params" ]
  }
}

[JoshuaKGoldberg]

Oh yes, that's correct! Whoohoo!