Images not working after using another workspace in separate tab

[aonnikov]

Steps to reproduce:

1. Open workspace ws1
2. Open workspace ws2 in separate tab in browser
3. Try to open some issue with attached image in the first tab

Expected: images are displayed Actual: images are not displayed, image API returns 500

Explanation: Image API looks for token in presentation-metadata-Token cookie in the request. When opened another workspace in separate tab, the cookie had been overridden with ws token and as a result the first tab started using wrong token.

[aonnikov]

Reopened because the fix was invalid.