rename explorer ng -> explorer in readme and package.json #597

Job	Run time
javadoc-spotbugs-codeql	4m 41s
build-and-test-nflow-explorer	4m 18s
build-and-test (17)	1m 26s
build-and-test (20)	1m 16s
integration-tests (17, h2)	2m 5s
integration-tests (17, mariadb)	2m 11s
integration-tests (17, postgresql)	2m 43s
integration-tests (17, mysql)	3m 33s
integration-tests (17, sqlserver)	4m 45s
integration-tests (17, db2)	4m 9s
integration-tests (17, oracle)	3m 55s
integration-tests (20, h2)	1m 56s
integration-tests (20, mariadb)	2m 19s
integration-tests (20, postgresql)	2m 24s
integration-tests (20, mysql)	2m 43s
integration-tests (20, sqlserver)	3m 49s
integration-tests (20, db2)	5m 1s
integration-tests (20, oracle)	4m 28s
	57m 42s

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