Fix URL encoding issues in pysvn when viewing diffs in the UI

Review Request #10671 — Created Aug. 30, 2019 and updated — Latest diff uploaded

Review Board

Resolve URL encoding issue for pysvn that results in diffs not being displayable in the UI if the file's path contains a '#' (and possibly other special URL characters, such as '?')

The original code appeared to append the file path to the repo URL, then parse the result as a URL in order to URL-encode the file path. This is nonsensical, so most of the code has been removed and replaced with simply URL-encoding the path before appending it to the SVN repository URL.

Please see [here|] for more context on the issue.

Currently running in our production server. No known side-effects so far.