feat(back): add logger decorator

[spy4x]

Right now LogService usage is a nasty overwhelming boilerplate.

Every controller's endpoint and command/query/event handler function look like this:

async methodName(...params): ReturnType {
    return this.logger.trackSegment(this.methodName.name, async () => {
      ... actual code ...
    }, {params});
  }

It would be neat to simplify this to just:

@Logger()
async methodName(...params): ReturnType {
      ... actual code ...
}