feat(): add an option for post processing compiling

Using the optional directive attribtue `translate-compile`, the result of a translation will be recompiled.

For example:

```json
{
  "text": "<span>{{name}} is a citizen of <strong ng-bind=\"world\"></strong>!</span>"
}
```

and

```html
<p translate="text" translate-compile translate-values="{name: \'The Doctor\'}"></p>
```

this will result into (given a scope variable `world = 'Gallifrey'` the element text `The Doctor is a citizen of Gallifrey!` respectively in the corresponding HTML.