Send debug header showing where the redirect was made (#223)

* feature: send debug header
closes #222

* tweak: fix phpstan errors

* tweak: defensive maximum attempts

* tweak: improve static analysis

* build: update dependencies

* build: php 8.1 compatibility

* ci: specify phpunit version

* ci: specify phpstan version

* ci: specify phpstan version

* ci: quick fix for stream uri

feature: async response methods for #220 (#221)

* feature: async response methods for #220

* build: build with 8.1 compatibility

* tweak: allow more public methods

tweak: internal status code could be null

Upload files using FormData (#214)

* wip: add formdata class

* wip: add urlsearchparams class

* feature: implement URLSearchParams

* feature: tweak urlsearchparams

* wip: extract KeyValuePairStore

* wip: implement KeyValuePairStore for FormData

* wip: improve tests by expecting warning to be emitted

* wip: empty formdata options

* wip: test submitter is included in the form submission

* wip: test constructing with square brackets

* wip: fix static analysis error on DOMNodeList

* wip: implement form types

* wip: remove unused constants

* feature: implement promise-based functions
closes #208

* test: improve static tests

* wip: uploading of files for #213

Formdata, URLSearchParams (#212)

* wip: add formdata class

* wip: add urlsearchparams class

* feature: implement URLSearchParams

* feature: tweak urlsearchparams

* wip: extract KeyValuePairStore

* wip: implement KeyValuePairStore for FormData

* wip: improve tests by expecting warning to be emitted

* wip: empty formdata options

* wip: test submitter is included in the form submission

* wip: test constructing with square brackets

* wip: fix static analysis error on DOMNodeList

* wip: implement form types

* wip: remove unused constants

* feature: implement promise-based functions
closes #208

* test: improve static tests

Ci matrix builds and QA tooling (#209)

* stan: better type hints for query strings

* build: upgrade stan

* build: upgrade phpunit

* build: upgrade phpunit

* test: introduce phpmd, phpcs

* ci: upgrade ci

* build: update dependencies

* build: branch alias

* build: branch alias

* build: bump version

* build: bump version

* build: bump version

* build: bump version

* build: branch alias

* build: branch alias

* build: fix test error

CI & QA - introduce PHPMD and PHPCS (#203)

* test: code sniffer passing

* test: mess detector - remove unused function

* test: mess detector passing

* test: pass unit tests

* ci: introduce ci build matrix

* test: use enum name

feature: request factory creates uri with all parts (#183)

* feature: request factory creates uri with all parts

* test: fix existing tests

* stan: cast int properly

feature: expose headers as public readonly property (#176)

Update README.md (#174)