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
```
operatorList,
      executionStartIdx,
      continueCallback,
      stepper
    ) {
      const argsArray = operatorList.argsArray;
      const fnArray = operatorList.fnArray;
      let i = executionStartIdx || 0;
      const argsArrayLen = argsArray.length;
      
      if (argsArrayLen === i) {
        return i;
      }
      const chunkOperations =
        argsArrayLen - i > EXECUTION_STEPS &&
        typeof continueCallback === "function";
      const endTime = chunkOperations ? Date.now() + EXECUTION_TIME : 0;
      let steps = 0;
      const commonObjs = this.commonObjs;
      const objs = this.objs;
      let fnId;
      while (true) {
        if (stepper !== undefined && i === stepper.nextBreakPoint) {
          stepper.breakIt(i, continueCallback);
          return i;
        }
        fnId = fnArray[i];
        if (fnId !== OPS.dependency) {
          this[fnId].apply(this, argsArray[i]);