Apply filters to the items query

[dmolineus]

At the moment the filters passed by the request (usually bbox filter), is only handled after the items are loaded. A simple query filter is not possible because each layer renderer could require different items.

The idea to improve it is:

• Create an OrFilterRule where each renderer will add its filter.
• If a renderer does not support filters, it should add a filter which forces loading everything. (Maybe customizable in the backend so that it simply accepts the data being filtered by other renderers).
• Each renderer have to check each item again when render them because their could be data which is outside of the filter (As the MarkerRederer already does to filter markers).