Add icon for Solid.ByRuledLoft

[mmisol]

Purpose

Adds icons created by Jingyi for the new node Solid.ByRuledLoft.

Here is a screenshot of how they look like in Dynamo:

Declarations

Check these if you believe they are true

• The codebase is in a better state after this PR
• Is documented according to the standards
• The level of testing this PR includes is appropriate
• User facing strings, if any, are extracted into *.resx files
• All tests pass using the self-service CI.
• Snapshot of UI changes, if any.
• Changes to the API follow Semantic Versioning and are documented in the API Changes document.
• This PR modifies some build requirements and the readme is updated

Reviewers

@QilongTang @aparajit-pratap

[aparajit-pratap]

@mmisol I think you also need to check in the icon png files.

[mmisol]

@aparajit-pratap They are embedded into the resx file

[aparajit-pratap]

We do check them in here: https://github.com/DynamoDS/Dynamo/tree/master/src/Resources/ProtoGeometry. Also the node description does not match: https://git.autodesk.com/Dynamo/LibG/blob/dc73830fad6f0ef274af0c306cbc0592aa234088/LibG.Interface/IGeometryFactory.cs#L879

[aparajit-pratap]

@mmisol I think I know why the node description has not been updated. The code comments in IGeometryFactory.cs need to also be copied to ProtoGeometry. We have to do this manually for now as the T4 template auto-generation is broken currently. Hoewever, we can make that change later. If you could just add the png's, we can merge this PR.