Configuration:
- PDF.js version: 2.0.550

Steps to reproduce the problem:
1. Render document in SVG mode `renderMode="svg"`

What is the expected behavior? (add screenshot)
Rendering annotations same way as they rendered on canvas

What went wrong? (add screenshot)
```
Warning: Unimplemented operator beginAnnotations
Warning: Unimplemented operator endAnnotations
```
});
    messageHandler.on("PasswordRequest", exception => {
      this._passwordCapability = createPromiseCapability();
      if (loadingTask.onPassword) {
        const updatePassword = password => {
          this._passwordCapability.resolve({
            password,
          });
        };
        try {
          loadingTask.onPassword(updatePassword, exception.code);
        } catch (ex) {
          this._passwordCapability.reject(ex);
        }
      } else {
        this._passwordCapability.reject(
          new PasswordException(exception.message, exception.code)
        );
      }
      return this._passwordCapability.promise;
    });
    messageHandler.on("DataLoaded", data => {
      
      
      if (loadingTask.onProgress) {
        loadingTask.onProgress({
          loaded: data.length,
          total: data.length,
        });
      }