Improve selection of Data sources - Local data sources

jirikadlec2[CodePlex]
To add a local data source, I go to Select Data Sources - Local Data Source - Add Data source..

This shows the data sources window. After I add a new local data source, it shows the 'Manage data sources' window.

This works well for the first time (if I have 0 local data sources)
But it doesn't work well for second time (i don't know if my data source was previously added)

Suggested fix (short-term): If I click Add Data Source and a local data source exists, show the 'Manage Data sources' window.

Suggested fix (long-term): Integrate the content of the existing 'Manage Data Sources' window into the 'Data Sources' dialog as a part of re-design of data sources selection in search.

Start at the desktop workflow Select Data Sources → Local Data Source → Add Data Source and trace how the Data Sources and Manage Data Sources windows handle an existing local source. Confirm the behavior when a local data source already exists, then make the short-term flow open Manage Data Sources and verify both first-time and subsequent additions.

Written by the indexing model from the issue text.