[4.x] Support arrays in wrap modifier

[jacksleight]

This PR allows you to pass arrays to the wrap modifier. So you can do:

{{ test = "one two" }
{{ test | wrap('span') }}
{{ test | explode(' ') | wrap('span') | join(' ') }}

Resulting in:

<span>one two</span>
<span>one</span> <span>two</span>

[jackmcdade]

I like it!