Issue #2867960 by Eric_A, Mile23, Jo Fitzgerald, mpdonadio: Merge Component composer.json files to account for them during build

Issue #2935137 by el7cosmos, Mixologic: License "GPL-2.0+" is a deprecated SPDX license identifier, use "GPL-2.0+-only" or "GPL-2.0+-or-later" instead

Issue #2776235 by mikeryan, alexpott: Cached autoloader misses cause failures when missed class becomes available

Issue #2337283 by hussainweb, Mile23, alexpott, aleksip, dawehner, heykarthikwithu, naveenvalecha, Crell, xjm, davidwbarratt, Fabianx, jhedstrom, tim.plunkett, larowlan, tstoeckler: Add a composer.json file to every component