Finalize workspace -> devworkspace renaming

[sleshchenko]

We renamed workspace CR to devworkspace CR but there are places which still use workspace:

• workspace_id, name labels;
• .status.workspaceId;
• devworkspace CR docs references to workspace
• maybe even more.

[sleshchenko]

The dependents components which needs to be updated:

• Devfile API
• Controller itself
• DevWorkspace Che Operator
• DevWorkspace Client
• Dashboard
• Che Theia
• Che machine exec

[sleshchenko]

Postponing to next milestone since we don't have enough time to do it before 0.2.0, and it should be pretty safe to postpone and finish without a rush.