Support string body in the generic request method #1098

Job	Run time
run-test-suite (ubuntu-latest, 3.13, latest)	10m 5s
run-test-suite (ubuntu-latest, 3.9, latest)	9m 42s
run-test-suite (ubuntu-latest, 3.9, 9.4)	12m 6s
run-test-suite (ubuntu-22.04, 3.7, 9.1)	9m 35s
	41m 28s

Provide feedback