feat: Add global logger object

[webJose]

Fixes #54

[Copilot]

Pull Request Overview

This PR adds a global logger object to the routing library, allowing users to control logging behavior during initialization. The logger can be disabled, use the default console, or accept a custom logger implementation.

• Adds an ILogger interface defining the required logging methods (debug, log, warn, error)
• Implements a configurable logger system with support for boolean flags and custom logger objects
• Updates existing code to use the new logger instead of direct console calls

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/lib/types.ts	Defines the ILogger interface with required logging methods
src/lib/index.ts	Adds logger option to InitOptions and calls setLogger during initialization
src/lib/core/Logger.ts	Implements the logger system with stock, off, and custom logger support
src/lib/core/Logger.test.ts	Comprehensive test coverage for the logger functionality
src/lib/core/LocationState.svelte.ts	Updates warning message to use the new logger
src/lib/core/LocationState.svelte.test.ts	Updates test to mock the new logger instead of console
src/lib/core/LocationFull.ts	Updates warning message to use the new logger

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