[epic] Support registry+v1 bundle installation in SingleNamespace and OwnNamespace install modes

[ncdc]

• Add alpha feature gate #1751
• Initial annotation-based implementation #1752
• Harden registry+v1 to manifest conversion (unit) testing #1753
• Update ClusterExtension API to support bundle installation configuration #1750
• Add extensible values field to Extension spec #612
• Support watchNamespaces in the template schema of registry+v1 bundles #613
• Set condition if watchNamespaces is set and package doesn't support that mode #614

[oceanc80]

Add ytt config

• This should use the same method as used in OLM v0 (annotation key: 'olm.targetNamespaces')
• Look into if watchNamespaces can be passed as parameters to ytt

[LalatenduMohanty]

• We should figure-out the use-cases we want to solve with this epic.