feat: add return type for queries

[danielknell]

Description

Adds a generic Query type that can be extended to define the return type of dispatching the query.

Fixes #99

Motivation and Context

The current Any response has a type does not allow static analysis of the returned value.

How Has This Been Tested?

Manually tested with mypy and vscode type inference (pyright) to check desired type is infered, defaulting to Any.

Screenshots:

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING.md document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[Copilot]

Pull Request Overview

This PR introduces a new generic Query type to improve type inference for query responses, replacing the previous use of Any. Key changes include:

• Adding a new covariant type variable ReturnType_co and Query protocol to declare query return types.
• Updating the query() method signature in the message bus to use the new Query[T] and generic return type.
• Adjusting documentation and tests to reflect the updated typing and usage of queries.

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/banshee/bus.py	Introduces Query protocol and updates type annotations in query()
docs/usage/dispatching-requests.md	Updates documentation with examples for using the new Query type
src/banshee/init.py	Exports the new Query type
docs/conf.py	Updates Python intersphinx mapping
tests/unit/test_message_bus.py	Adjusts test annotations for query() return type
tests/unit/test_traceable_bus.py	Adjusts test annotations for query() return type

[Copilot]

The example snippet defines 'GetUserQuery' twice, which could be confusing. Consider removing or clarifying one of the definitions to avoid ambiguity.

Suggested change

	class GetUserQuery(banshee.Query[User]):
	user_id: int