Replacing dict to werkzeug.datastructures.MultiDict for request args in ...

Support for multiselect, multiple checkboxes with the same name attribute in html. For example: in my first page with some list of users with phone numbers, I has a multiple select input field for filter users by phone numbers. The request args string after filtering looks like: "?phones=1234567&phones=7654321&phones=5673212", but in paginate links href attribute I has only one phone since the python dict type does not support non-unique keys. To solve this problem you can use a MultiDict structure from werkzeug.datastructures instead of the standard dictionary python type.