Support ContextClassLoader when loading optional classes #4268

Job	Run time
build-and-verify (2.5, 8, ubuntu-latest)	6m 39s
build-and-verify (2.5, 11, ubuntu-latest)	4m 40s
build-and-verify (3.0, 8, ubuntu-latest)	7m 3s
build-and-verify (3.0, 11, ubuntu-latest)	5m 20s
build-and-verify (3.0, 17, ubuntu-latest)	4m 49s
build-and-verify (3.0, 21, ubuntu-latest)	4m 18s
build-and-verify (3.0, 22, ubuntu-latest)	3m 51s
build-and-verify (4.0, 8, ubuntu-latest)	7m 46s
build-and-verify (4.0, 11, ubuntu-latest)	5m 8s
build-and-verify (4.0, 17, ubuntu-latest)	4m 32s
build-and-verify (4.0, 21, ubuntu-latest)	11m 13s
build-and-verify (4.0, 22, ubuntu-latest)	3m 52s
build-and-verify (2.5, 8, windows-latest)	5m 52s
build-and-verify (3.0, 8, windows-latest)	6m 47s
build-and-verify (4.0, 8, windows-latest)	7m 38s
build-and-verify (2.5, 8, macos-latest)	3m 54s
build-and-verify (3.0, 8, macos-latest)	4m 30s
build-and-verify (4.0, 8, macos-latest)	4m 0s
	1h 41m 52s

Provide feedback