Add new object/array-destructuring options to typedef rule

[shlomiassaf]

PR checklist

• Addresses an existing issue: object destructuring assignment should have a dedicated option for the [typedef] rule #1039
• New feature, bugfix, or enhancement
  • Includes tests
• Documentation update

What changes did you make?

This PR adds support for opting in to object-destructuring and array-destructuring in typedef rule.

Current variable-declaration option, if on, will fail if:

const [ paramA, paramB ] = [15, 'test'];

With this PR it wont, variable-declaration only fails on simple non-binding declarations.

Tests samples:

const { paramA, paramB } = { paramA: "test", paramB: 15 };
                        ~    [expected object-destructuring: '{ paramA, paramB }' to have a typedef]

const { paramA, paramB }: { paramA: string, paramB: number } = { paramA: "test", paramB: 15 };

const [ paramA, paramB ] = [15, 'test'];
                        ~    [expected array-destructuring: '[ paramA, paramB ]' to have a typedef]

const [ paramA3, paramB3 ]: { number: string, paramB1: string } = [15, 'test'];

Is there anything you'd like reviewers to focus on?

variable-declaration now has it's own test directory.

[palantirtech]

Thanks for your interest in palantir/tslint, @shlomiassaf! Before we can accept your pull request, you need to sign our contributor license agreement - just visit https://cla.palantir.com/ and follow the instructions. Once you sign, I'll automatically update this pull request.

[nchen63]

add destructuring cases without typedefs. Also this typedef doesn't match

[shlomiassaf]

@nchen63 good catch, copy/paste :)
updated.

[nchen63]

@shlomiassaf thanks!

[shlomiassaf]

@nchen63 I think now it is required in typedef-whitespace
not sure I will have the time for this...