flutter_package / flutter_wakelock

* Added web support

* Use JS interop library; Add null check for releasing WakeLockSentinel;

* Update dependencies

* Update dependencies

* Refactoring

* Update gitignore

* Format wakelock_web folder

* Remove unused JS variable

* Bump github action versions

* Bump checkout version

* Update checks.yml

* Use relative changelog

Co-authored-by: creativecreatorormaybenot <creativecreatorormaybenot@gmail.com>