Full-text search, filtering resources by text layer

After implementing https://github.com/ARK-Builders/arklib-android/issues/64 it will be possible to filter resources basing on text query and their text layer. Addition UI elements should be added for this, or probably tag selector could be reused.

Text search also could search in `description` metadata attributes.

Start by reading the prerequisite arklib-android issue #64 and inspecting the existing tag selector mentioned here. The work is complete when users can filter resources using a text query against the text layer and description metadata, with suitable Android UI controls.

Written by the indexing model from the issue text.