feat(ngSwitch): Allow multiple case matches for one element

Now you can also use an array in `ng-switch-when`, which allows
specifying multiple values for the same element. Values will
be evaluated within the scope when using the array notation.

I.e. `ng-switch-when='[1, 3, 'hello', 5-3]'`

Each element will switch only once even if there are multiple
matches in the same element.

BREAKING CHANGE: Previously `ng-switch-when` expressions that
matched against square brackets strings won't work anymore.
The fix is encapsulate the string into a one-element array.

I.e. before `ng-switch-when='[hi]'`, now `ng-switch-when="['[hi]']"`

Closes #3410