kinescope 1.3.0

Refactor Kinescope into modular API client with player/media/popup submodules

Rework the module from a monolithic media provider into a layered architecture: a low-level Kinescope API client core with optional presentation submodules.

- Introduce KinescopeClient, KinescopeClientInterface, and KinescopeVideo for direct Kinescope API access (token and tokenless modes), plus a settings form, routing, services, permissions, and menu links.
- Drop the drupal:media dependency and bump core requirement to ^10 || ^11.
- Add kinescope_player: field type/widget/formatter, validation constraint, and player renderer with configurable embed method (iframe, IFrame API, Web Components).
- Add kinescope_media: media source plugin with API title autofill and poster download, plus KinescopeAddForm.
- Add kinescope_popup: dialog playback via controller, access checker, popup formatter, and trigger/popup templates.
- Add config schemas and update hook 10001 enabling the player/media submodules and migrating the embed_type setting.
- Rewrite README documenting architecture, installation, migration from the single-module version, and configuration of API token and embed method.