## 🚀 Feature Proposal

#7753 added basic support for WebAuthn automation in the form of the `addVirtualAuthenticator` and `removeVirtualAuthenticator` methods. Implement the rest of the methods: `addCredential`, `getCredential`, `removeCredential`, `removeAllCredentials`, `setUserVerified`.

## Motivation

Support more WebAuthn use-cases, like logging in with a specific credential, handling user verification failures, and inspecting generated credentials.

## Example

For a page like this

```html
<button id="login">Log in with WebAuthn</button>
<span id="result"></span>
```

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

A test could be written like so:

```java
// Set up the virtual authenticator.
HasVirtualAuthenticator virtualAuthenticatorManager = ((HasVirtualAuthenticator) driver);
VirtualAuthenticatorOptions options = new VirtualAuthenticatorOptions();
VirtualAuthenticator authenticator =
    virtualAuthenticatorManager.addVirtualAuthenticator(options);

// New code: inject a credential into the authenticator.
// Without this API the developer would have to generate a credential through
// navigator.credentials.create({...}) on the javascript side and would have less
// control over the resulting PK.
Credential credential = Credential.createNonResidentCredential(...params);
virtualAuthenticatorManager.addCredential(authenticator, credential);

// Assert login successful:
driver.findElement(By.id("login")).click();
WebElement result = driver.findElement(By.id("result"));
new WebDriverWait(driver, 60, 1000).until(
    driver -> !result.getText().equals(""));
assertThat(result.getText()).isEqualTo("Success!");
```
* @param method The request method.
     * @param parts The parsed request path segments.
     * @return Whether this instance matches the request.
     */
    boolean isFor(HttpMethod method, ImmutableList<String> parts) {
      if (!this.method.equals(method)) {
        return false;
      }
      if (parts.size() != this.pathSegments.size()) {
        return false;
      }
      for (int i = 0; i < parts.size(); ++i) {
        String reqPart = parts.get(i);
        String specPart = pathSegments.get(i);
        if (!(specPart.startsWith(":") || specPart.equals(reqPart))) {
          return false;
        }
      }
      return true;
    }
    void parsePathParameters(ImmutableList<String> parts, Map<String, Object> parameters) {
      for (int i = 0; i < parts.size(); ++i) {
        if (pathSegments.get(i).startsWith(":")) {
          parameters.put(pathSegments.get(i).substring(1), parts.get(i));
        }
      }
    }
  }
}