Fix project format to .net SDK style

[Tom-Kingstone]

NOTE: Depends on

Issues addressed by this PR

Closes #262

Test files

fix project format to allow "dotnet build" to work for this project.

Changelog

Additional comments

Personally I have always thought it weird that this toolkit still has the old format, so it's good that there's a simple process to do it now.

[Tom-Kingstone]

@BHoMBot check required

[bhombot-ci]

@Tom-Kingstone to confirm, the following actions are now queued:

• check code-compliance
• check documentation-compliance
• check project-compliance
• check core
• check null-handling
• check serialisation
• check versioning
• check installer

There are 86 requests in the queue ahead of you.

[Tom-Kingstone]

@BHoMBot check project-compliance
@BHoMBot check installer

[bhombot-ci]

@Tom-Kingstone to confirm, the following actions are now queued:

• check project-compliance
• check installer

There are 12 requests in the queue ahead of you.