Install MCE using extra manifests at install time (connected)

User Story:

As a customer, I want to be able to:

• Install MCE with the agent-installer

so that I can achieve

• create an MCE hub with my openshift install

Acceptance Criteria:

Description of criteria:

• Upstream documentation including examples of the extra manifests needed
• Unit tests that include MCE extra manifests
• Ability to install MCE using agent-installer is tested
• Point 3

(optional) Out of Scope:

We are only allowing the user to provide extra manifests to install MCE at this time. We are not adding an option to "install mce" on the command line (or UI)

Engineering Details:

• (optional) https://github/com/link.to.enhancement/
• (optional) https://issues.redhat.com/link.to.spike
• Engineering detail 1
• Engineering detail 2

This requires/does not require a design proposal.
This requires/does not require a feature gate.