Updated to support finding .slnx solution file and allow DbContextFac…

[ejohnson-dotnet]

Updated to support finding .slnx solution file and allow DbContextFactory to find correct folder.

Description

Resolves #xxxx (write the related issue number if available)

Fixes issue of finding solution folder if only .slnx file exists. Fixes DbContextFactory to always find the correct folder.

Checklist

• [x] I fully tested it as developer / designer and created unit / integration tests
• [x] I documented it (or no need to document or I will create a separate documentation issue)

How to test it?

Please describe how this can be tested by the test engineers if it is not already explicit - or remove this section if no need to description.