Direct links to gateway should preserve filenames

[lidel]

This is a continuation of #49

When user adds a file its name becomes a link to the resource at the public gateway, however the link uses RAW CID instead of IPFS Path within wrapping directory that preserves the filename:

• Current URL: https://ipfs.io/ipfs/Qmayz4F4UzqcAMitTzU4zCSckDofvxstDuj3y7ajsLLEVs
• Expected URL: https://ipfs.io/ipfs/QmVnLkRxWWv2xiPKeQy6re1zCepzX7YXUiq5fESkd1j8bC/bug_or_feature.jpg