Allow admin to add eMQ as a proxy

[bajiat]

User story

As an admin user I want to add eMQ proxy to my deployment so that real-time apis can be managed through the UI.

Goal

API admin can add eMQ proxy to the deployment through Proxies view. Admin is able to add the following configuration information for the eMQ broker:

• eMQ proxy URL
• eMQ Elasticsearch (analytics) endpoint
• eMQ API URL
• eMQ API credentials

[kyyberi]

Excellent! Nice that we are approaching eMQ proxy usage via platform!

[bajiat]

@frenchbread Can you add an estimate to this issue?

[frenchbread]

@bajiat Added estimation