Replaced the bundled sqlite sources with the ones retrieving the lib from the official website.

[KOLANICH]

[SRombauts]

Hello @KOLANICH I actually don't think it's a good idea to not have a copy of SQLite3 source code directly on the. I also cannot request all users to move to such a recent CMake 3.14, it's not supported by popular CI systems

Perhaps could you make the Fetch feature optional?

Cheers!