Add new Timing block to app loading track message

[lbwexler]

Add new Timing block to app loading track message.

• New state for 'Authenticating'
• Misc cleanups

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[amcclain]

This is very nice, thank you!

Would it be worth splitting up INITIALIZING to distinguish between HOIST_INITIALIZING and APP_INITIALIZING - transitioning to the latter right before we call await this.appModel.initAsync();?

Wasn't sure how much logic might be out there (if any) that keys off of that state.

[lbwexler]

Great catch!!

[lbwexler]

Went for the suggested additional states. Think we should go ahead and leverage all this, and I doubt anyone was observing it specifically.