HG-188: Streamline request handling

Includes some refactoring on handling requests. Added some tests to fully cover `Utils.ts`

* catchall routes are removed as they were made obsolete by `/{title*}`;
* `indexRoutes` are handled by one function;
* all methods interfaces are unified;
* `backendTimeout` variable is created in `localSettings.ts` to allow setting the HTTP request timeout; 
* added logging for failed HTTP requests;
* added several test cases to improve the `Utils.ts` coverage;