Fix HTTP client handling and configuration in Typesense PHP client

[tharropoulos]

Change Summary

What is this?

This PR fixes an issue with HTTP client handling in the Typesense PHP client library where
PSR-18 compatible clients were being unnecessarily wrapped and recreated on every request.
This improves performance and provides better compatibility with different HTTP client
implementations.

Changes

Code Changes:

1. In src/Lib/Configuration.php:

   • Fixed client instance caching to avoid creating new instances on every request
   • Added proper handling for different HTTP client types:
     • Direct use of HttpMethodsClient instances without wrapping
     • Smart wrapping of PSR-18 and HttpClient implementations
   • Improved type hints and error messaging for invalid client configurations
   • Added validation for client implementations

2. In tests/Feature/HttpClientsTest.php (New):

   • Added tests for client configuration scenarios:
     • Default client discovery behavior
     • PSR-18 client compatibility
     • Direct HttpMethodsClient usage
     • Invalid client validation

Documentation Updates:

1. In .gitignore:
   • Added .env and typesense-data to ignore local development files

Context

This fixes issue #77 reported by @ragusa87 where passing a PSR-18 client instance
to the configuration would fail with:

TypeError: Http\Client\Common\HttpMethodsClient::__construct(): Argument #1 
($httpClient) must be of type Http\Client\HttpClient, Http\Discovery\Psr18Client given

The fix ensures proper handling of different client types while maintaining backward
compatibility and improving performance by avoiding unnecessary client wrapping and
recreation.

PR Checklist

• I have read and signed the Contributor License Agreement.