Extend the list of embedded plugins for internal Open VSX registry

[svor]

Is your task related to a problem? Please describe

Workspaces with Che-Code should provide the same functionality by plugins as it was done with Che-Theia editor.

For this when we have offline VS Code plugin registry, we'll need to extend the list of the embedded plugins: https://github.com/eclipse-che/che-plugin-registry/blob/b03f8b6d46a02275d6ae06a3c24cc871015f89c4/openvsx-sync.json.

Describe the solution you'd like

Go through the list of plugins that we have for Che-Theia, check if a plugin exists on https://open-vsx.org/ and add it into the list of embedded plugins by its id

[svor]

There is a problem with starting local openVSX