Fix issue #1427 | UtilityAreaTerminal model changed to ObservableObject

[kmohsin11]

Description

1. When the user presses the "-" button to close the selected terminal tab, the app crashes. This was not happening everytime. The crash is reproducible if the app is idle for a while and then the tab was removed.
2. If a terminal tab is in editable state(rename state) and then remove/minus button is tapped the app crashes.

Related Issues

closes #1427

• 🐞 Removing terminal tab crashes app #1427

Checklist

• I read and understood the contributing guide as well as the code of conduct
• The issues this PR addresses are related to each other
• My changes generate no new warnings
• My code builds and runs on my machine
• My changes are all related to the related issue above
• I documented my code

Screenshots

Screen.Recording.2023-11-29.at.10.30.48.AM.mov

[thecoolwinter]

Changes mentioned on discord:

• The root problem is caused by passing terminal as a binding on line 195 of UtilityAreaTerminalView.swift
• I'd like to keep UtilityAreaTerminal a struct, as it should be treated with value semantics and copied rather than shared and mutated like a class in this context.
• The change to id being a constant is smart.

Once these couple things are changed I'll happily merge!

[thecoolwinter]

After some discussion @kmohsin11 and we realized trying to juggle around structs to keep semantics ended up being more complicated than it was worth.

[austincondiff]

Looks good, thank you!

[austincondiff]

@allcontributors add @kmohsin11 for bug

[allcontributors]

@austincondiff

I've put up a pull request to add @kmohsin11! 🎉