Null safety feature request

[naumanmir]

Dear FlutterBleLib team,

  Please update the package to null safety. Or any idea when it will get an update?

[AlexZurek]

Looks like there is an open PR for this #605 that is waiting for review.

[MoralCode]

it appears the current dev branch supports it courtesy of #586, just hasn't been released to pub.dev yet