Adapt to changes in web API

[thekid]

This pull request makes the library compatible with the upcoming xp-forge/web version 5.0, see xp-forge/web#121:

• Input::uri() -> Input::resource() renaming
• Logging API refactoring
• Dropped support for PHP < 7.4, see Drop PHP 7 support xp-framework/rfc#343
• WebSockets support. TODO: Check whether this can be done via a single AWS lamba function at all, otherwise yield errors

[thekid]

This should be bumped to the release version once it's available

[thekid]

TODO: Check whether this can be done via a single AWS lamba function at all

This should be doable by exposing the lambda via a) HTTP API and b) Websockets gateways. Unfortunately, this means the wss://-URL differs from the https://-URL, and we would need to send a redirect instead of the Connection: upgrade headers. Needs some real-life testing!