## 🚀 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.
* @param method The HTTP method to use for the command.
   * @param pathPattern The URI path pattern for the command. When encoding a command, each
   *     path segment prefixed with a ":" will be replaced with the corresponding parameter
   *     from the encoded command.
   */
  @Override
  public void defineCommand(String name, HttpMethod method, String pathPattern) {
    defineCommand(name, new CommandSpec(method, pathPattern));
  }
  @Override
  public void alias(String commandName, String isAnAliasFor) {
    aliases.put(commandName, isAnAliasFor);
  }
  protected void defineCommand(String name, CommandSpec spec) {
    checkNotNull(name, "null name");
    nameToSpec.put(name, spec);
  }
  protected static CommandSpec delete(String path) {
    return new CommandSpec(HttpMethod.DELETE, path);
  }
  protected static CommandSpec get(String path) {
    return new CommandSpec(HttpMethod.GET, path);
  }
  protected static CommandSpec post(String path) {
    return new CommandSpec(HttpMethod.POST, path);
  }
  private String buildUri(
    String commandName,
    SessionId sessionId,
    Map<String, ?> parameters,