Fix Binding with IDictionary<,> implementer types

[tarekgh]

Fixes#77246

In .NET 7.0 we have done some refactoring work in the configuration binding code #68133. The refactored code work fine when binding to IDictionary<,> interface or Dictionary<,> based class but it broke the case when using a type which implementing IDictionary<,> interface. The new code was always creating Dictionary<,> type and then getting the setter of the Item property from that type. But the object used in the binding is not of type Dictionary<,> at all and the property setter fails because it is used with wrong type.

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Issue Details

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Fixes #77246

In .NET 7.0 we have done some refactoring work in the configuration binding code #68133. The refactored code work fine when binding to IDictionary<,> interface or Dictionary<,> based class but it broke the case when using a type which implementing IDictionary<,> interface. The new code was always creating Dictionary<,> type and then getting the setter of the Item property from that type. But the object used in the binding is not of type Dictionary<,> at all and the property setter fails because it is used with wrong type.

Author:	tarekgh
Assignees:	-
Labels:	area-Extensions-Configuration
Milestone:	-

[tarekgh]

CC @SteveDunn

[SteveDunn]

LGTM - sorry I didn't address the issue myself but I'm a bit busy in my day job right now.

[tarekgh]

/backport to release/7.0

[github-actions]

Started backporting to release/7.0: https://github.com/dotnet/runtime/actions/runs/3430573766