[dotnet] Fallback result parsing of script execution to expected type

[nvborisenko]

Description

Executing JS in browser may return result of different types. I have added new conditional thread to try casting of result to expected type.

It is not a breaking change, this change can be considered as "now trying one more way".

Motivation and Context

Fixes #11801

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• I have read the contributing document.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[diemol]

Thank you, @nvborisenko!