Add new fields in CheCluster CR to configure VS Code marketplace

Is your enhancement related to a problem? Please describe

Currently che is using https://open-vsx.org but as for Airgapped mode, offline, etc we have a way to use OpenVSX instance embedded in the plug-in registry.

Then Admin should be able to configure the registry to use

so , che-code is able to get the value and see if it configures the registry to open-vsx.org or a corporate OpenVSX or something else

Part of https://github.com/eclipse/che/issues/20549

Describe the solution you’d like

spec:
   components:
     devWorkspace
     cheServer
     pluginRegistry:
       deployment
       disableInternalRegistry
       externalPluginRegistries
+      OpenVSXURL: https://openvsx.org # If not set use the embedded one
     devfileRegistry
     database
     dashboard
     imagePuller
     metrics
   containerRegistry
   gitServices
   devEnvironments
   networking

Describe alternatives you’ve considered

any change/suggestion is welcomed

we only need to know when cheCode is booting the URL to use to fetch the VSIX files 😃

Additional context

No response

[l0rd]

spec:
   components:
     devWorkspace
     cheServer
     pluginRegistry:
       deployment
       disableInternalRegistry
       externalPluginRegistries
+      externalOpenVSXRegistryURL: https://openvsx.org # If not set use the embedded one
     devfileRegistry
     database
     dashboard
     imagePuller
     metrics
   containerRegistry
   gitServices
   devEnvironments
   networking

[tolusha]

https://github.com/eclipse-che/che-operator/pull/1466