Use ClientInterface instead of HttpClient

[glaubinix]

Q	A
Bug fix?	no
New feature?	no
BC breaks?	yes
Deprecations?	no
Related tickets	addresses one more item of #439 (comment)
Documentation	if this is a new feature, link to pull request in https://github.com/php-http/documentation that adds relevant documentation
License	MIT

What's in this PR?

Instead of using the deprecated HttpClient interface, this now uses ClientInterface everywhere

Why?

The old interface is deprecated

Checklist

• Updated CHANGELOG.md to describe BC breaks / deprecations | new feature | bugfix
• Documentation pull request created (if not simply a bugfix)

To Do

• I am not sure if keeping around both httplug.client.default and httplug.psr18_client.default is OK or if this will cause any issues? If we can keep them around, then it might be easier for people to update the library without running into issues.

[dbu]

thanks a lot!

i have one small nitpick on the naming in the test.

[dbu]

thanks!

we should update a few things on https://docs.php-http.org/en/latest/integrations/symfony-bundle.html and https://docs.php-http.org/en/latest/integrations/symfony-full-configuration.html (sources are at https://github.com/php-http/documentation/tree/main/integrations)

[glaubinix]

Yes, that was on my list. How do you generally handle cases that are different in versions, e.g. removed config keys?

[dbu]

generally it would be best if we had a separate documentation for each major version, but the doc is for all the various components together so no meaningful versioning is possible.

i would just remove obsolete things, and have ..versionadded:: 2.0 notes for new things (see for example components/client-common.rst)

mostly people will read the doc when setting things up. for BC breaks the changelog of the corresponding repository is the right place.