Missing error message when pushing load type that is not implemented in Lusas.

#### Description:

- When pushing a load type that is not implemented an error message regarding Null property is presented to the user.
- It is (for the user) unclear why that error arises.
- It would simplify if an error stating that the load type is not implemented for pushing to Lusas.

#### How to fix:
- When the method determines the load type it could default to a message telling the user if it is not implemented.

Add this line in the end of the `loadType` case checks.
`Engine.Base.Compute.RecordError("Load type is not supported in the Lusas_Toolkit.");`

Question is if it should be worded as _not supported_ or _not implemented_.

https://github.com/BHoM/Lusas_Toolkit/blob/a680c5bf863f7d08c0e71569fbfc97781f6d9515/Lusas_Adapter/CRUD/Create/Create.cs#L112-L140

Test script:

https://burohappold.sharepoint.com/:u:/r/sites/BHoM/02_Current/12_Scripts/01_Issue/BHoM/Lusas_Toolkit/%23385%20Error%20message%20for%20unsupported%20loadtypes%20.gh?csf=1&web=1&e=BUncCR

#### Additional info:
The load types (BHoM Type) not supported according to the wiki on Lusas_Toolkit: `PointAcceleration`, `PointVelocity`, `BarPrestressLoad`, `ContourLoad` and `GeometricalLineLoad`.