config var uniformity

[qrkourier]

The inconsistency between these names is stumbling block for learners:

• ZITI_CTRL_ADVERTISED_ADDRESS
• ZITI_CTRL_ADVERTISED_PORT
• ZITI_ROUTER_ADVERTISED_ADDRESS
• ZITI_ROUTER_PORT

A minimal solution would be to introduce ZITI_ROUTER_ADVERTISED_ADDRESS as a replacement for ZITI_ROUTER_PORT while continuing to allow ZITI_ROUTER_PORT to function as an alias for the new var.

My personal preference is less minimal and aims for slightly improved aesthetics by shortening the other three, which are still unambiguous now that we're prescribing a single address and port as a best practice (thanks, ALPN):

• ZITI_CTRL_ADDRESS
• ZITI_CTRL_PORT
• ZITI_ROUTER_ADDRESS
• ZITI_ROUTER_PORT