Change Bundle.entry from List to IList.

[mmsmits]

It will be easier this way to write performant helper methods this way, to query for specific types of resources in a Bundle for example.

This is a breaking change, so we should schedule this when we are planning the next major release.

[mmsmits]

Maybe:

• Only a couple of lists like Bundle.entry (not all lists). To implement an observable collection.

https://learn.microsoft.com/en-us/dotnet/api/system.collections.objectmodel.observablecollection-1?view=net-8.0
or
https://learn.microsoft.com/en-us/dotnet/api/microsoft.visualstudio.extensibility.ui.observablelist-1?view=vs-extensibility

Other candidates:

• Composition.entry
• List.entry
• Group (?).
• Maybe more?