Add base comm path selection in UI

In communication path creation dialog, add button Add Base Path besides the Add Link button.

Adding the base path adds the item to the left side at the bottom which represents the base path as well as locks the last lists source ID to the receiver of the base path.

Selecting that base path item opens the form on the right that looks similar to the select comm path dialog.

• Source selector component. When user selects a source, it searches the existing communication paths and displays in the list below.
• List with comm path search results. When an item is selected, switches to a single item view.
• sequence number field which can be left blank

1. Fix rating reason list to show base path properly
2. Restrict searched paths to that proposition or document
3. If source is entered for last link, filter search results to paths that end in that source