feat(gui): visualise invalid regions of torque map

[t-bre]

Description

Visualise invalid regions of the torque map by colour indication and warning messages.

Tasks

• Highlight clipped regions in red.
• Highlight regions with a negative gradient in orange.
• Add textual indication of the reason a region is considered invalid.

Additional Notes

• This could be done either by creating some kind of "curve validator" class which can be passed to the GraphComponent for generic validation functionality, or by a virtual method of GraphComponent which gets passed the interpolated path and which derived classes implement to do the validation logic.
• Invalid regions could be visualised by overlaying a transparent coloured rectangle over the invalid area of the graph, similar to the deadline. Alternatively a coloured line could be drawn following the curve.
• Warning messages could be displayed as tooltips with a short message.