This patch removes enterprise license support and moves
move_chunk() function under community license (TSL).
Licensing validation code been reworked and simplified.
Previously used timescaledb.license_key guc been renamed to
timescaledb.license.
This change also makes testing code more strict against
used license. Apache test suite now can test only apache-licensed
functions.
Fixes#2359
Reloading shared libraries (which is done to start parallel
workers) is done is the order in which load_file completes.
If we try to load the TSL from PG_init, this causes postgres to
attempt to load the TSL before timescale itself, which causes an
error.
Also disables the warning on normal TSL startup.
