Glance Image Member Management

Summary
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Currently Horizon does not allow to share images between different projects. We have "Share With me" container in project image tab, but currently ability to share image is not possible in horizon. It should be enabled, which is why this blueprint is written.

Motivation
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The Glance API provides the ability to manage the membership of images, enabling the ability to privately share images to specific projects. This functionality should be exposed through Horizon.

Description
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After this feature added on, the following capabilities will be provided:
- Administrator can share an image between different projects.
- Image owner can share an image between different projects.
- Administraor and image owner can add and delete member to specific image.
- End users (members) can see the shared image in their "Share With Me" container at image tab and can launch an instance from these shared images.

UX
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N/A

Testing
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1- As administrator(or image owner) go to the image tab.
2- Click on image name to see image detail page
3- Two tab will be shown : 1- Overview 2- Member
4- Click on the member tab
5- Add a new member(e.g. demo tenant) to the current image
6- Log-in as end user in target project that the image was shared to(e.g. demo tenant)
7- Got to image tab
8- You can see the shared images in "Share With Me" container

Outside Dependencies
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N/A

Requirements Update Required
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N/A

Doc Impact
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N/A