[DependencyInjection] made some perf improvements

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | yes
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | n/a

This PR optimizes the creation of dumped containers drastically (thanks @jpauli for the hint).

The Container class generated by the PHP dumper does not include the `getDefaultParameters()` method anymore. It does not seem like a big deal to me as I fail to see a use case where someone would override this method.