`virtual_ymca_editor` should not be hardcoded

[froboy]

Example:
https://github.com/fivejars/openy_gated_content/blob/master/src/SegmentContentAccessCheck.php#L23
fivejars#187

From @anpolimus: Probably we have to add general trait.

From @froboy: It'd be great for that to be alter-able as well. For instance, we have a "site owner" role that adds some specific Y Cloud permissions and it'd be nice for us to be able to add that to the list of roles considered "Editors" via a hook or other configuration.

[froboy]

#78 is now the working solution to this.

[froboy]

fivejars#188 resolve this issue.