Fix missing module error

Fix inverted code and statusCode, and use the "Required client library
plugin not present" [1] error code (which we currently use when the
vcdiff plugin is missing).

[1] https://github.com/ably/ably-common/blob/main/protocol/errors.json

src/common/lib/util/utils.ts

@@ -569,5 +569,5 @@ export function arrEquals(a: any[], b: any[]) {
 }
 
 export function throwMissingModuleError(moduleName: keyof ModulesMap): never {
-  throw new ErrorInfo(`${moduleName} module not provided`, 400, 40000);
+  throw new ErrorInfo(`${moduleName} module not provided`, 40019, 400);
 }