Enable ambient mode

Motivation

To future-proof Big Bang's service mesh implementation, we're migrating to Istio's ambient operation mode.

Acceptance Criteria

• This package in ambient mode must interop with other packages regardless of whether or not they are also in ambient mode
• Ambient mode must be togglable for this package
• All Istio resources must be created by bb-common's istio implementation
• Any L7 features currently in use in sidecar mode must be removed
• Any init container shenanigans within containers due to legacy istio requirements (istio-proxy quitquitquit basically) must be removed