Circle Radius & Diameter
Icons representing:
- The radius of a circle (This is distinct from #451 which is talking about border radius).
- The diameter of a circle.

The use case that lead me to this was a need for a Pipe Diameter icon and I designed this as a more generic equivalent. Could also be used for maths.

**References**

![Icon Diameter](https://github.com/user-attachments/assets/ae4b6d9f-13ae-45e1-845b-308eb0e8fb07)
![Icon Radius](https://github.com/user-attachments/assets/ed7b3719-3dc4-4ae3-bc22-9be0be5c2fb8)
https://www.flaticon.com/free-icon/diameter_7535794

**Additional context**

I created these SVGs by mashing together the notched circle and arrow icons, feel free to use these if that helps!

![Radius SVG](https://github.com/user-attachments/assets/a9360523-7cd1-4ce3-b571-b7c53eeeef1a)
![Diameter SVG](https://github.com/user-attachments/assets/59f93422-e19f-40e3-b66e-ddf5c2b2d520)
