Attach (recommended) or Link to PDF file here:
https://bitcoin.org/bitcoin.pdf

Configuration:
- Web browser and its version: all
- Operating system and its version: all
- PDF.js version: tested with 2.9.11, but most likely all versions
- Is a browser extension: no

Steps to reproduce the problem:
1. Type "a purely" (single space between "a" and "purely") - doesn't find anything
2. Type "a  purely" (two spaces between "a" and "purely") - finds the phrase

Sometimes even 3 spaces are necessary.

What is the expected behavior? (add screenshot)
![Screenshot from 2021-04-08 13-00-03](https://user-images.githubusercontent.com/6362989/114008903-57639a00-986b-11eb-903a-92bbebbd922b.png)

What went wrong? (add screenshot)
![Screenshot from 2021-04-08 13-01-53](https://user-images.githubusercontent.com/6362989/114008810-44e96080-986b-11eb-8232-f58a62ed7899.png)

This affects many PDFs because justify alignment is common enough.
if (width > 0) {
        const scale = textDivProperties.canvasWidth / width;
        if (this._enhanceTextSelection) {
          textDivProperties.scale = scale;
        }
        transform = `scaleX(${scale})`;
      }
    }
    if (textDivProperties.angle !== 0) {
      transform = `rotate(${textDivProperties.angle}deg) ${transform}`;
    }
    if (transform.length > 0) {
      if (this._enhanceTextSelection) {
        textDivProperties.originalTransform = transform;
      }
      textDiv.style.transform = transform;
    }
    if (textDivProperties.hasText) {
      this._container.appendChild(textDiv);
    }
    if (textDivProperties.hasEOL) {
      const br = document.createElement("br");
      br.setAttribute("role", "presentation");
      this._container.appendChild(br);
    }
  }
  /**
   * @private
   */
  _render(timeout = 0) {