Let sendSms() name the esm_class messaging mode (#92)

* Regression tests for the messaging mode on sendSms()

* Let sendSms() name the esm_class messaging mode

* Document the messaging mode option and the decision behind it

* Name the constants move for migrating consumers and share the refusal's value naming

* Cover the messaging-mode refusals through submitSms()

* Refuse transaction mode and a report under datagram mode on sendSms()

* Narrow the mode checker and name the default mode once

src/error-from.ts

@@ -8,3 +8,8 @@ export function errorFrom(reason: unknown): Error {
 		return new Error('A thrown value that cannot be converted to a string');
 	}
 }
+
+/** String() throws on a null-prototype object or a symbol, so only a string or number is printed. */
+export function namedValue(value: unknown): string {
+	return typeof value === 'string' || typeof value === 'number' ? String(value) : typeof value;
+}