Solver: Introduce variable sources for installed bundles

[jmprusi]

For the operator-controller solver to resolve whether an upgrade path is possible, we need to feed all the currently installed operators into the input variables, to do so, we will need to map the current BundleDeployments to the solved catalog package version.

To map the BundleDeployment into the correct Catalog package, the operator-controller can add a new annotation on all created BundleDeployments containing a key formed by something similar to: $operatorName-$operatorVersion-$operatorChannel.

This information has to be fed into the operator-controller solver input so a proper solution can be found after implementing the constraints documented on #267

Part of #231