fix(init), rewrite workspace.jsonc if missing

[davidfirst]

Currently, if the worksapce.jsonc is missing, it throws an unclear error:

workspace.jsonc is missing the "teambit.workspace/workspace" property

And bit init doesn't fix it.

Now, the error is clearer:

fatal: workspace config is empty. probably one of bit files is missing. consider running "bit init"

And running bit init rewrite the file.