[FEATURE] Enable sub-domain support in HAProxy

[freephile]

Is your feature request related to a problem? Please describe.

In QualityBox, I made a note:

There are 3 ways of configuring HAProxy for websockets:

1. Proxy based on subdomain
2. Proxy based on URI
3. Proxy using Websocket detection

We use this last approach, but should add at least subdomain processing to enable subdomain mode in Meza

Describe the solution you'd like

Describe alternatives you've considered

Additional context