Add Progress Indicators to MRTK3

[AMollis]

This issue has been migrated a new MRTK repository, and the status of this issue will now be tracked at the following location:

• Add Progress Indicators to MRTK3 MixedRealityToolkit/MixedRealityToolkit-Unity#130

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Overview

Port the MRTK2 progress indicators (doc) to MRTK3.

Tasks

• Add a loading bar indicator similar to MRTK2's (doc)
• Add rotating orbs indicator similar to MRTK2's (doc)
• Add object display indicator similar to MRTK2's (doc)

[AMollis]

@AMollis dupe this

[AMollis]

Closing as dupe of:

• Add Progress Indicator to MRTK3 #11480