Assertions for verifying the data types of arrays

[jasonmccreary]

This PR is inspired by #16067. It provides this functionality by adding an assertJsonTypedStructure method on the TestResponse class.

For example, the following JSON response:

{
   "name": "Jason McCreary",
   "age": 38,
   "height": 6.1,
   "male": true,
   "attributes": {
      "hair":"brown",
      "eyes":"brown"
   },
   "hobbies": ["programming", "woodworking", "cooking"],
   "languages": [
      {"name":"PHP"},
      {"name":"JavaScript"}
   ]
}

Could be verified with:

$response->assertJsonTypedStructure([
    'name' => 'string',
    'age' => 'integer',
    'height' => 'number',
    'male' => 'boolean',
    'attributes' => [
        'hair' => 'string',
        'eyes' => 'string',
    ],
    'hobbies' => 'array'
    'languages' => [
        '*' => [
            'name' => 'string',
        ]
    ],
]);

The underlying verification of the array structure was also broken out to a generic assertArrayStructure method on the AdditionalAssertions trait.