Bump year in copyright information to 2022 and adjust same scripts
to reference NOTICE that didn't have the reference yet.
This patch also removes orphaned test/expected/utils.out.
Clarify better how source code is split between Apache 2.0 and Timescale
License, to now serve as a reference file to which GitHub will point. Also
cleanup NOTICE to point to LICENSE files.
The dblink extension is blacklisted by some cloud-hosting providers and
is an unnecessary dependency for single-node operation. Since we don't plan
to use dblink to implement clustering this PR removes the dependency.