Issue #10267, parameter bag array access

[DependencyInjection] Added access to array elements via dot notations.

| Q             | A
| ------------- | ---
| Bug fix?      | [no]
| New feature?  | [yes]
| BC breaks?    | [no]
| Deprecations? | [no]
| Tests pass?   | [yes]
| Fixed tickets | #10267
| License       | MIT
| Doc PR        | [The reference to the documentation PR if any]

- [ ] submit changes to the documentation