Registry Architecture Refactoring - Enhanced Separation of Concerns (#46)

* refactor: Separate Registry concerns following SOLID principles [WIP]

- Extract ReferenceProvider and ReferenceRegistryInterface interfaces
- Create DefaultToolExecutor with ReferenceHandlerInterface
- Remove execution responsibility from Registry class
- Enable custom handler and executor implementations

* refactor: implement SOLID principles with separated execution concerns

* Create DefaultResourceReader, DefaultPromptGetter
* Refactor JsonRpc Handler and RequestHandlers to use dedicated executors
* Update ServerBuilder to support custom executors via dependency injection

* chore: remove extra comments

* feat: introduce DispatchableRegistry for enhanced tool and resource management

* refactor: use proper interfaces

* refactor: implement HandlerInterface for improved abstraction and flexibility

* test: add unit tests for DispatchableRegistry and Registry classes

* refactor: cover with unit tests Resource reader, Prompt getter and Tool executor

* cs fix

* phpstan fix

* test: add unit tests for CallToolHandler, GetPromptHandler, PingHandler, and ReadResourceHandler

* refactor: revert Handler

* chore: remove style guide for tests

* refactor: remove "Default" prefix from classes

* refactor: remove DispatchableRegistry

* refactor: use package specific exception classes

* refactor: remove DispatchableRegistry

* refactor: add logger support to PromptGetter and ResourceReader classes

* Update src/Capability/Prompt/PromptGetter.php

Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>

* refactor: Use FQN for Resource class to avoid cs-fixer misinterpreting it as `resource`

* refactor: rename ToolExecutor to ToolCaller and related classes for clarity and consistency

* refactor: add missed docblock

* refactor: rename ToolExecutor references to ToolCaller

* refactor: rename ToolCallerTest property and variable references

* cs fix

* ignore some phpstan errors

---------

Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>

src/Server/RequestHandler/ListPromptsHandler.php

@@ -11,7 +11,7 @@
 
 namespace Mcp\Server\RequestHandler;
 
-use Mcp\Capability\Registry;
+use Mcp\Capability\Registry\ReferenceProviderInterface;
 use Mcp\Schema\JsonRpc\HasMethodInterface;
 use Mcp\Schema\JsonRpc\Response;
 use Mcp\Schema\Request\ListPromptsRequest;
@@ -24,7 +24,7 @@ use Mcp\Server\MethodHandlerInterface;
 final class ListPromptsHandler implements MethodHandlerInterface
 {
     public function __construct(
-        private readonly Registry $registry,
+        private readonly ReferenceProviderInterface $registry,
         private readonly int $pageSize = 20,
     ) {
     }