Solution can't load if hypen is used in the name

- .NET SDK Version:
net6

Template version: Latest of todays date (8 June 2021)

Steps to Reproduce:

1. Install template via terminal/cmd
2. Create new project with hyphen ( - ) i.e. my-service

Project fails to load due to some naming in the .sln gets named my_service (underscore instead of hyphen)

edit: found that this is reported as a bug (and it's been a while):
[Dash - in sourceName gets changed to underscore _ inside files but not in file names](https://github.com/dotnet/templating/issues/1168)

Reproduce the template installation and project creation steps with a hyphenated name such as my-service, then inspect the generated .sln naming. Read the linked templating issue #1168 for the related behavior. Done means the generated solution loads successfully and uses consistent hyphen or underscore naming.

Written by the indexing model from the issue text.