[BrowserKit | WCM] added override power to server parameters provided on request method

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #9527, #9762
| License       | MIT
| Doc PR        | maybe if @WouterJ give me a chance