crmResURL, crmResPath - Allow full path expressions

crmResURL, crmResPath - Allow full path expressions

Before
------

In Smarty, there is no way to request values from `Civi::paths()`.

After
-----

In Smarty, you can request values from `Civi::paths()` using these notations:

```
{crmResURL expr="[civicrm.root]/foo"}
{crmResPath expr="[civicrm.root]/foo"}
```