[v9] Check for unimplemented error during stream receive in Client.GetAccessRequests

[xacrimon]

Backport #13459 to branch/v9

[r0mant]

@xacrimon Linter fails on this PR:

client/client_test.go:754:16: m.NewClient undefined (type *mockAccessRequestServer has no field or method NewClient) (typecheck)
	clt, err := m.NewClient(ctx)
	              ^
client/client_test.go:741:4: unknown field `addr` in struct literal (typecheck)
			addr:                           l.Addr().String(),
			^
client/client_test.go:754:16: m.NewClient undefined (type *mockAccessRequestServer has no field or method NewClient) (typecheck)
	clt, err := m.NewClient(ctx)
	              ^
client/client_test.go:741:4: unknown field `addr` in struct literal (typecheck)
			addr:                           l.Addr().String(),
			^
client/client_test.go:754:16: m.NewClient undefined (type *mockAccessRequestServer has no field or method NewClient) (typecheck)
	clt, err := m.NewClient(ctx)

[xacrimon]

@r0mant Backported the needed utilities to make this test run.