[WIP]Add filter interface to any filterable resource view

Currently, the only way to add filters to resource view is when they're inside a `ckanext-dashboard`. Ideally, we could add these filters anywhere a filterable resource view is displayed.
Just to clarify, there's also an option of using another index type for non-textual columns, like b-tree, trigrams, etc. I wouldn't use them on the `q` parameter though, as it'll be inconsistent. What I mean is that, for example, if you want to search for strings starting with `foo`, you'd do `foo:*`when using full-text search, and `foo%` when using a LIKE search. There's no concept of a `plain` search when using LIKE as well.

These differences will make the API unconsistent. If we decide to go that route, I would create another parameter, and leave `q` just for full-text search.