Peripheral: GPIO: Rename some at90_tiny_mega enums to streamline with xmega.

PullType -> Configuration.
TriggerType -> InputTrigger.
Core: xmega: Move utils.hpp/.cpp into core.
Peripheral: GPIO: Give the InputTrigger its own method.

This is more consistent with xmega, etc...
Tools: DFG: Fix gpio search error for xmega.
Core: Avr: Refactor xmega interrupts to use enum classes.
Peripheral: GPIO: Add xmega gpio template.