Review routing of gpio analog I/O through caravel_core and caravan_core 

Analog I/O signals are routed like digital signals through `caravel_core` and `caravan_core` with minimal line width, no restriction on layers changes, and no shielding.

<img width="952" alt="caravel analog routing" src="https://github.com/user-attachments/assets/357cad07-797b-4716-aa34-41010e71eb89" />

@DavidRLindley @RTimothyEdwards @passant5 