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 curr = context.iCurr;
    const iFirstSave = curr - 3;
    const iFirstTransform = curr - 2;
    const iFirstPIXO = curr - 1;
    const firstPIXOArg0 = argsArray[iFirstPIXO][0];
    const firstTransformArg0 = argsArray[iFirstTransform][0];
    const firstTransformArg3 = argsArray[iFirstTransform][3];
    
    
    const count = Math.min(
      Math.floor((i - iFirstSave) / 4),
      MAX_IMAGES_IN_BLOCK
    );
    if (count < MIN_IMAGES_IN_BLOCK) {
      return i - ((i - iFirstSave) % 4);
    }
    
    const positions = new Float32Array(count * 2);
    let iTransform = iFirstTransform;
    for (let q = 0; q < count; q++, iTransform += 4) {
      const transformArgs = argsArray[iTransform];
      positions[q << 1] = transformArgs[4];
      positions[(q << 1) + 1] = transformArgs[5];
    }
    
    const args = [
      firstPIXOArg0,
      firstTransformArg0,
      firstTransformArg3,
      positions,