Add "filter" selector to the collection view

**Is your feature request related to a problem? Please describe.**

Given a large number of entries in a collection that have different taxonomies (like blog posts or products) it can become unmanageable to quickly find an entry belonging to a certain taxonomy or matching a criterion.

**Describe the solution you'd like**

Ideally the end user should be able to filter the displayed entries of a collection using a filter dropdown.
The filters should come in two flavors.

1. (Added in #3741, thanks @BA1RY & @erezrokah)
Fixed filters that have preconfigured conditions and apply across the whole collection, similar to how the filter attribute works. They can have a label and would be bundled in a single filter menu like so:


2. Dynamic filters that would use the same logic as the "group by" option proposed in #3614 allowing the user to select a field to filter a collection by. This can for example be select or relation field that provides it's own options. Those should then have their own drop down for filtering.


**Describe alternatives you've considered**

1. Allowing the user to define searchable fields that also respect the widgets such as displayFields for the query
2. If #2056 is happening this provide a (non optimal way) of splitting the collection in subfolders that could at least be grouped by taxonomies

**Additional context**

In this context it is probably also useful to spice up the filter framework to allow for more precise filtering, such as checking if value is in / not in a predefined list, if a number / date is <,<=,>,>=, etc. This probably warrants it's own issue.

Additionally it would habe to be defined for custom fields how they can contribute by providing their available options.