Fix Mesh provider selection

[didierofrivia]

At the moment the controller is relying on having IstioOperator CRD in the cluster and if not, it chooses to install OSSM. This is far from ideal, for many reasons, starting with having a CRD in the cluster doesn't mean Kuadrant needs to make decisions based on that to it's impossible to switch from one to the other. The selection needs to come from configuration in Kuadrant spec possibly.

Notes:
RFC: Kuadrant/architecture#7

[didierofrivia]

Thanks to the work done in #645, #859, #944 among other PRs, we can close this issue and focus on Kuadrant/architecture#7