Simplify the Sentry configuration

Summary:
Provide a Zemke-Rhyne execution module method to build the Sentry DSN.

That allows to configure Sentry for a service by giving 3 parameters:

• realm: the Sentry realm to determine server host
• project_id: last part of the URL, an integer with the project to target
• credential: the zr credential for Sentry

Test Plan: Test with notifications container

Reviewers: dereckson

Reviewed By: dereckson

Differential Revision: https://devcentral.nasqueron.org/D2013