Use a single command to for uninstall of mesh and cluster wide resources

[shashankram]

Please describe the Improvement and/or Feature Request

There are 2 commands pertaining to uninstall:

1. osm uninstall mesh that uninstalls the control plane
2. osm uninstall cluster-wide-resources that uninstalls the cluster wide resources such as CRDs created after install

Having uninstall split across 2 commands seems unnecessary to me. This issue proposes to update the osm uninstall command to do the following:

1. osm uninstall --all to delete the mesh and cluster wide resources (equivalent to osm uninstall mesh && osm uninstall cluster-wide-resources
2. osm uninstall simply removes the mesh (equivalent to osm uninstall mesh)

Scope (please mark with X where applicable)

• CLI Tool [X]