Support MGC requirements to configure Redis' URL for limitador

[alexsnaps]

This is possibly impacting #164

[alexsnaps]

@maleck13 Did you have something on this already? i.e. how would Kuadrant's Limitador server be configured to use the Elasticache instance?

[maleck13]

No I think we just worked around it by configuring redis in limitador directly cc @R-Lawton.
I guess if installing kuadrant the question is whether we expose it from the kuadrant CR or not. My thoughts would be that we use a secret to store the connection credentials and a ref can be passed to that secret in the kuadrant cr?

[alexsnaps]

We're currently pondering multiple options, as discussed in the weekly meeting (see Petr's item). @eguzki will start with #164 to address this "in its entirety", but start with this bit. So that this issue will try to have the parts of the full solution for MGC to use… hopefully - so whatever comes out of this is to be "draft", but address the problem.

[Boomatang]

A proposed solution to this problem is outline in Kuadrant/architecture#25, it would be good if everyone could have a look at it.