Use common approach to disallow deleting current project and domain

Disabling and deleting currently-logged-in project and domain need to be handled with same method.
Stricktly speaking, we should use the same policy for the following actions:
- Disable current project
- Delete current project
- Disable current domain
- Delete current domain
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To handle the above actions, two different strategies exist:
1- Disallow users to do the action
2- Allow to do, but handle the error
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Current status of the aboved mentioned actions is as follows:
- Disable current project(Disallowed) --->https://review.openstack.org/#/c/138383/
- Delete current project(Allowed) --->https://review.openstack.org/#/c/199410/
- Disable current domain(Allowed) ---> (I reported the bug: https://bugs.launchpad.net/horizon/+bug/1494448)
- Delete current domain(Allowed but if domain is disabled)
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Using the same method for all of the above actions is what we should do to avoid inconsistency in Horizon UI.