Sync 10.5.2021.

[franzihei]

• I'm prolonging the sourcify.dev domain today (wow, it's been a year already guys!!)

[FabijanC]

• fixed input bug in UI draft (https://github.com/ethereum/sourcify/pull/463)
• above average amount of user feedback, part of them related to library link support (https://github.com/ethereum/sourcify/pull/105)
• UI and Remix plugin displayed invalid repo links if address for verification was all lowercase (https://github.com/ethereum/sourcify/pull/460)
• saving contracts without an embedded metadata hash in their bytecode as partial matches (https://github.com/ethereum/sourcify/issues/465)