Fix DocumentEngine line behaviors in Diffusion
Ref T13105. Fixes some issues with line linking and highlighting under DocumentEngine:
- Adding $1-3 to the URI didn't work correctly with query parameters.
- Reading $1-3 from the URI didn't work correctly because Diffusion parses them slightly abnormally.
Test Plan: Clicked/dragged lines to select them. Observed URI. Reloaded page, got the right selection.
Reviewed By: mydeveloperday
Maniphest Tasks: T13105
Differential Revision: https://secure.phabricator.com/D19305