Enable envelope encryption cache metrics collection

[robobario]

Caffeine does support micrometer [1][2], so we should make a ticket to enable this to be switched on.

Originally posted by @robobario in https://github.com/kroxylicious/kroxylicious/pull/944#discussion_r1480484001

We can expose cache metrics via micrometer. We should make this something the user can configure (on by default?). There are also two binders that produce different granularity of metrics.

[gracegrimwood]

This should default to the same state (metrics on/off) as the Kroxylicious instance. Needs thought about how filter can tell if metrics are on.

[k-wall]

https://github.com/kroxylicious/kroxylicious/issues/313 is discussion whether filters should have the ability to contribute their own metrics.