Fix configuration binding with types implementing IDictionary<,>

[tarekgh]

The configuration binder already working with the types which implement IDictionary<,>. The problem happens when such types include members with the same names as the members of IDictionary<,>. At that time will throw AmbiguousMatchException.

#78938

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Issue Details

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The configuration binder already working with the types which implement IDictionary<,>. The problem happens when such types include members with the same names as the members of IDictionary<,>. At that time will throw AmbiguousMatchException.

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

[SteveDunn]

LGTM

[eerhardt]

This LGTM.

I just have some nits on existing code now that this has been tweaked.

[halter73]

Can we add a test case to ensure a non-settable custom IReadOnlyDictionary implementation gets skipped over?

[tarekgh]

CI failure is unrelated. merging it.

[tarekgh]

/backport to release/7.0

[github-actions]

Started backporting to release/7.0: https://github.com/dotnet/runtime/actions/runs/3579305346

[github-actions]

@tarekgh backporting to release/7.0 failed, the patch most likely resulted in conflicts:

$ git am --3way --ignore-whitespace --keep-non-patch changes.patch

Applying: Fix configuration binding with types implementing IDictionary
Applying: Apply suggestions from code review
Applying: Address the feedback
Applying: more feedback
error: sha1 information is lacking or useless (src/libraries/Microsoft.Extensions.Configuration.Binder/src/ConfigurationBinder.cs).
error: could not build fake ancestor
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0004 more feedback
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".
Error: The process '/usr/bin/git' failed with exit code 128

Please backport manually!

[github-actions]

@tarekgh an error occurred while backporting to release/7.0, please check the run log for details!

Error: git am failed, most likely due to a merge conflict.