fix airlocks inconsistently auto-closing after unbolting

[slarticodefast]

About the PR

The autoclose timer is now correctly being reset after unbolting an opened door.
Two scenarios in which this bug previously occured on master:

A:

• spawn an airlock and emag
• emag the airlock
• open the wirepanel and use a multitool to pulse the bolts wire to unbolt the door
• the door won't autoclose until closed manually

B:

• spawn an airlock and command door remote
• walk into the airlock so it opens, then activate the bolts using the remote so it stays open
• if you wait less than 5 seconds to unbolt again, then the door will wait a while until closing
• if you wait more than 5 seconds to unbolt, the door will close immediately

Why / Balance

bugfix

Technical details

Added DoorBoltsChangedEvent and raise it in SetBoltsDown.
Subscribe to it in SharedAirlockSystem to update the auto-close timer.
Added a Dirty() into SetNextStateChange so the timer is correctly networked.
Added the readonly ViewVariables attribute to the NextStateChange variable in DoorComponent to make debugging it easier.

Requirements

• I have read and am following the Pull Request and Changelog Guidelines.
• I have added media to this PR or it does not require an ingame showcase.

Breaking changes

none

Changelog
🆑

• fix: Fixed doors not auto-closing correctly after being unbolted in an open state.