Add fields option

This task is part of story #7687 REST endpoint to list project's git repositories

Change-Id: I199de26a1730375a8089fe3a11580c304ef08835
Merge commit 'refs/changes/08/3408/12' of ssh://gerrit.tuleap.net:29418/tuleap into stable

* ssh://gerrit.tuleap.net:29418/tuleap:
  Add fields option
This is Tuleap 7.8.99.30

Change-Id: I2fbbb735f048b9013410f64adda5dc03963f871b