Add support for Glibc version 2.28

Summary:
The Glibc backward compatibility feature handles up to version 2.27
(used by Ubuntu Bionic). This diffs adds support for the version 2.28
(used by Debian Buster).

There is an additional compatibility fix involved due to the update of
fcntl() and the introduction of the new fcntl64() function.
These functions are linked against their previous version through a
compatibility symbol.

Test Plan:
Cross build for all the linux platforms on an OS that ships Glibc 2.28
(tested on Debian Buster). Use both autotools and cmake for the
build.
Run the symbol-check.py script against the binaries and check there is
no complaint on fcntl or fcntl64 symbol being from a too recent
Glibc.
Check the binaries run on OS with a libc.so.6 version < 2.28

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D4167