Extract filters from objects and expression

It would be nice to be able to extract filters from expressions and object literals.
Like this:
```
<input placeholder="{{ a==b ? 'Hello'|translate : 0 }}"
```
and this
```
<input placeholder="{{ {first: ('Hello'|translate)} }}"
```

But I have some troubles with objects like this:
```
{{ {'first': ('Hello'|translate)} }}
```

Looks like it's impossible to write correct regexp without changing groups order.