When a service method is decorated with @hooks([]).params(...), hookMixin
now respects those custom params instead of overriding them with defaults.

This enables the use of custom method signatures:

  class MyService {
    @(hooks([]).params('userId', 'message'))
    async notify(userId: string, message: string) {}
  }

When registered with feathers, the notify method will have context.userId
and context.message available instead of the default context.data/params.

Changes:
- hookMixin checks for existing params from decorated methods
- For decorated methods, Feathers context (app, path, service, method)
  is added to the existing Context prototype instead of re-wrapping
- Added 5 tests for hookMixin respecting decorator params

Pending integration into main hooks documentation during v6-documentation rewrite.

- Add clone() method to HookManager for creating modified copies
- Refactor createChainableDecorator to use clone() instead of manual property copying
- Create createFeathersContextProps() helper to define Feathers context props once
- Add propsFromDescriptors() helper to convert PropertyDescriptorMap to HookContextData
- Tighten decorator types: use AnyFunction instead of Function, specify decorator context types
- Simplify hookMixin by using the shared helper functions

- Extract shared statusCodeDescriptor to avoid duplication
- Split into createFeathersProps() for HookContextData (standard path)
- Split into createFeathersDescriptors() for PropertyDescriptorMap (decorated path)
- Remove propsFromDescriptors() conversion function - no longer needed

Use clone().params/props/defaults() instead of directly accessing
internal _params/_props/_defaults properties.