Cloud tags selector

When maximized, tags selector should be capable of switching into alternative mode visually representing tags as a cloud. This mode will be called _cloud selector_ and normal mode will be called _linear selector_.

Both modes should operate on the same internal state, only visual representation should differ. Cloud selector allows to use more than 1 metric for ordering tags. The same as linear selector, cloud selector must hide or gray-out tags which are not actual with the current query.

In cloud selector, tags can have different sizes to represent some metric.

Cloud tags selector itself can come in 2 flavors:
* _2D cloud_ has 2 dimensions: size of a tag, and distance from center
* _3D cloud_ has 2 dimensions: horizontal, vertical and size of a tag.

Start by inspecting the existing maximized tags selector and its linear mode; the issue names no files or tests. Clarify whether the first deliverable is a 2D cloud, a 3D cloud, or both, then verify that linear and cloud modes share internal state and that inactive tags are hidden or grayed out.

Written by the indexing model from the issue text.