Topic Data Preview (by "eye" in navigation panel)

[ElenaAfina]

1. Add "eye" icon on hover on a topic in left navigation panel.
2. By clicking on this icon system shows standard Query panel.
3. Bottom preview contains table with topic data, columns: PartitionID, Offset, Timestamp Create, Timestamp Write, Key, Metadata, Message, Size.
4. It's better to hide Query Editor panel for topics as we don't have a possibility to write YQL queries for getting topics data.