Add encodepassword command to the CLI

Update the CLI so that `encodepassword <password>` can be used to
generate an encoded password.

Fixes gh-11875

spring-boot-project/spring-boot-cli/src/it/java/org/springframework/boot/cli/CommandLineIT.java

@@ -45,7 +45,7 @@ public class CommandLineIT {
 		assertThat(cli.await(), equalTo(0));
 		assertThat("Unexpected error: \n" + cli.getErrorOutput(),
 				cli.getErrorOutput().length(), equalTo(0));
-		assertThat(cli.getStandardOutputLines().size(), equalTo(10));
+		assertThat(cli.getStandardOutputLines().size(), equalTo(11));
 	}
 
 	@Test