Work around for UriFormatException caused by \\?\ prefix in the path

[buyaa-n]

When the path populated by AppDomain.CurrentDomain.BaseDirectory starts with \\?\ (long path prefix) Uri constructor throws UriFormatException: Invalid URI: The hostname could not be parsed which causing WinForms designer failure:

Moving the Uri creation code to where it is used and using Uri.TryCreate instead of the ctor

Please see the details from the issue: #70318

Fixes#70318

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Issue Details

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When the path populated by AppDomain.CurrentDomain.BaseDirectory starts with \\?\ (long path prefix) Uri constructor throws UriFormatException: Invalid URI: The hostname could not be parsed which causing WinForms designer failure:

Moving the Uri creation code to where it is used and using Uri.TryCreate instead of the ctor

Please see the details from the issue: #70318

Fixes #70318

Author:	buyaa-n
Assignees:	-
Labels:	area-System.Configuration
Milestone:	-

[buyaa-n]

/backport to release/6.0

[github-actions]

Started backporting to release/6.0: https://github.com/dotnet/runtime/actions/runs/2585103475