[Locale] Adding a deprecation note about the Locale component

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #12635 
| License       | MIT
| Doc PR        | -

As the class is deprecated, the `@deprecated` tag on methods should be removed.