## 🚀 Feature Proposal

Add support for the WebAuthn Automation API, a standard WebDriver extension that allows developers to create virtual authenticators to test websites using WebAuthn.

https://w3c.github.io/webauthn/#sctn-automation

_note: the above link may not work until https://github.com/w3c/webauthn/pull/1340 is merged_

## Motivation

At the moment there is no practical way to write e2e tests for pages using WebAuthn. Since this is a standard WebDriver API, the cost of implementing a layer on java is low.

## Example

For a page like this

```html
<button id="signup">Sign up with webauthn</button>
<span id="result"></span>
```

```javascript
document.getElmentById("signup").addEventListener("click", () => {
  navigator.credentials.create({...}).then(credentials => {
    document.getElementById("result").innerText = "Success!";
  })
});
```

A test could be written like so:

```java
// HasVirtualAuthenticator is an interface that augments a RemoteWebDriver.
HasVirtualAuthenticator virtualAuthenticatorManager = ((HasVirtualAuthenticator) driver);
VirtualAuthenticatorOptions options = new VirtualAuthenticatorOptions();
VirtualAuthenticator authenticator =
    virtualAuthenticatorManager.addVirtualAuthenticator(options);
driver.findElement(By.id("signup")).click();
WebElement result = driver.findElement(By.id("result"));
new WebDriverWait(driver, 60, 1000).until(
    driver -> !result.getText().equals(""));
assertThat(result.getText()).isEqualTo("Success!");
```

## Implementation

We can implement the AddVirtualAuthenticator and RemoveVirtualAuthenticator methods first since they're the most useful and follow up with the others in subsequent PRs.
* @see FileDetector
   * @see LocalFileDetector
   * @see UselessFileDetector
   */
  public void setFileDetector(FileDetector detector) {
    if (detector == null) {
      throw new WebDriverException("You may not set a file detector that is null");
    }
    fileDetector = detector;
  }
  public SessionId getSessionId() {
    return sessionId;
  }
  protected void setSessionId(String opaqueKey) {
    sessionId = new SessionId(opaqueKey);
  }
  protected void startSession(Capabilities capabilities) {
    Response response = execute(DriverCommand.NEW_SESSION(capabilities));
    Map<String, Object> rawCapabilities = (Map<String, Object>) response.getValue();
    MutableCapabilities returnedCapabilities = new MutableCapabilities();
    for (Map.Entry<String, Object> entry : rawCapabilities.entrySet()) {
      
      if (PLATFORM.equals(entry.getKey()) || PLATFORM_NAME.equals(entry.getKey())) {
        continue;
      }
      returnedCapabilities.setCapability(entry.getKey(), entry.getValue());
    }
    String platformString = (String) rawCapabilities.getOrDefault(PLATFORM,
                                                                  rawCapabilities.get(PLATFORM_NAME));
    Platform platform;