UploadedFile should include the file extension in its url

UploadedFile should include the file extension in its url
https://bugs.webkit.org/show_bug.cgi?id=174009

Reviewed by Chris Dumez.

Some command line tools such as darwinup use the file extension to determine the file type.
Include the file extension in the URL of an uploaded file to make it work with these tools.

* public/include/uploaded-file-helpers.php:
(format_uploaded_file): Include the file extension.
* public/v3/models/uploaded-file.js:
(UploadedFile):
(UploadedFile.prototype.url): Return the URL with hthe file extension specified. /api/uploaded-file
already supports having the file extension specified.
* server-tests/tools-sync-buildbot-integration-tests.js: Updated test cases.
* unit-tests/buildbot-syncer-tests.js: Ditto.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@218987 268f45cc-cd09-0410-ab3c-d52691b4dbfc