Add contract function for decentralized 'New Project' panel call

[Quazia]

This issue in combination with #1874 and #1876 should cover the following acceptance criteria:

• 'New project' panel allows users to switch between decentralized projects and GitHub
• If user is not connected to GitHub, request to connect will appear as designed

This will require contract level changes for the Projects app, a function call needs to be added. It's possible that the addRepo call can be recycled, but it's probably best to adjust the language, and ensure all data-points we were previously relying on github to capture are being represented in the contracts data (title, description). Some of this may be possible strictly modifying the IPFS, but this alone would require adding a CID to the addRepo call.