* ui: Don't show the CRD menu for read-only intentions
The UI bug here manifests itself only when a user/token is configured to have read-only access to intentions. Instead of only letting folks click to see a read only page of the intention, we would show an additional message saying that the intention was read-only due to it being 'Managed by [a kubernetes] CRD'. Whilst the intention was still read only, this extra message was still confusing for users.
This PR fixes up the conditional logic and further moves the logic to use ember-can - looking at the history of the files in question, this bug snuck itself in partly due to it being 'permission-y type stuff' previous to using ember-can and when something being editable or not was nothing to do with ACLs. Then we moved to start using ember-can without completely realising what IsEditable previously meant. So overall the code here is a tiny bit clearer/cleaner by adding a proper can view CRD intention instead of overloading the idea of 'editability'.