[HttpKernel] RequestDataCollector: collect data if the controller is a Closure

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | no
| License       | MIT
| Doc PR        | no

Use the same format as object methods to describe closures and collect the file and the line where it's been declared.

Currently, the `file` and `line` parameters are not shown by the webprofiler, but they could be useful to find a closure.