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>

tests/ServerTest.php

@@ -32,6 +32,7 @@ class ServerTest extends TestCase
             ->disableOriginalConstructor()
             ->onlyMethods(['process'])
             ->getMock();
+
         $handler->expects($this->exactly(2))->method('process')->willReturnOnConsecutiveCalls(new Exception(new \JsonException('foobar')), ['success']);
 
         $transport = $this->getMockBuilder(InMemoryTransport::class)