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
```
});
          const sendTest = () => {
            const testObj = new Uint8Array([
              this.postMessageTransfers ? 255 : 0,
            ]);
            
            
            try {
              messageHandler.send("test", testObj, [testObj.buffer]);
            } catch (ex) {
              warn("Cannot use postMessage transfers.");
              testObj[0] = 0;
              messageHandler.send("test", testObj);
            }
          };
          
          
          
          
          sendTest();
          return;
        } catch (e) {
          info("The worker has been disabled.");
        }
      }
      
      
      this._setupFakeWorker();
    }
    _setupFakeWorker() {