Replace GuzzleHttp with PSR-18 HTTP Clients

[flavioheleno]

This pull request replaces the Guzzle HTTP Client with PSR 17 and 18 interfaces. Closes #1019.

Changes to Dependencies:

• The dependencies psr/http-client, psr/http-factory, and psr/http-message were added to the require section.
• The guzzlehttp/guzzle package was moved to the require-dev section.

Changes to the AbstractProvider Class:

• Guzzle's HttpClientInterface was replaced with ClientInterface from the PSR-18 standard.
• Guzzle's RequestFactory was replaced with RequestFactoryInterface and StreamFactoryInterface from the PSR-17 standard.

Removal of the RequestFactory Class:

• The entire RequestFactory class was removed as it's no longer needed with the introduction of the PSR-17 standard interfaces.

[verfriemelt-dot-org]

what needs to happen to move forward with this? :)

[verfriemelt-dot-org]

i tested this with my application and can confirm that everything is working as expected so far for me 👍