Add QUERY HTTP method to the list of allowed methods

[dingo-d]

Pull Request Type

• I have checked there is no other PR open for the same change.

This is a:

• Bug fix
• New feature
• Documentation improvement
• Code quality improvement

Context

New HTTP method has been approved (https://www.rfc-editor.org/info/rfc10008/), this PR aims to add the support for it in the Requests lib.

Detailed Description

PR for issue #1074.

The PR adds new constant for the new HTTP method and the helper method that accompanies it.

I have also made a PR for the CI server for tests: RequestsPHP/test-server#13.

In the links I used www.rfc-editor.org instead of tools.ietf.org, I can change this if needed.

I tried testing locally, but had issues running the test server, so I'm hoping CI tests will pass once the CI server gets updated.

Quality assurance

• This change does NOT contain a breaking change (fix or feature that would cause existing functionality to change).
• I have commented my code, particularly in hard-to-understand areas.
• I have added unit tests to accompany this PR.
• The (new/existing) tests cover this PR 100%.
• I have (manually) tested this code to the best of my abilities.
• My code follows the style guidelines of this project.

Documentation

For new features:

• I have added a code example showing how to use this feature to the examples directory.
• I have added documentation about this feature to the docs directory.
  If the documentation is in a new markdown file, I have added a link to this new file to the Docs folder README.md file.

[jrfnl]

In the links I used www.rfc-editor.org instead of tools.ietf.org, I can change this if needed.

Please use the canonical source everywhere (whichever that is).