Small refactoring before adding multiple representations

[katehryhorenko]

BACKGROUND:
I'm planning to re-use code that creates Csg.Solid from SolidOperation

DESCRIPTION:
Solid creation is moved to a separate class

TESTING:

• I tested it on a few functions. I can share them with you.

REQUIRED:

• All changes are up to date in CHANGELOG.md.

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This change is 

[andrewheumann]

couple typos from the original comments, but otherwise

Reviewed 2 of 2 files at r2, all commit messages.
Reviewable status: complete! 1 of 1 approvals obtained (waiting on @katehryhorenko)

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Elements/src/Utilities/SolidOperationUtils.cs line 32 at r2 (raw file):

            var transform = transformed ? element.Transform : new Transform();

            // Transform the solid operatioon by the the local transform AND the

operatioon => operation (error from the original comment!)

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Elements/src/Utilities/SolidOperationUtils.cs line 42 at r2 (raw file):

            }

            // If an addition transform was proovided, don't forget

if an addition => if an additional
proovided => provided.