Test and review Watchdogs, CRC, EXTI and GPIO

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All implemented and tested except EXTI. Still figuring out the API for the peripheral

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CRC and GPIO tested and functional.

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EXTI integration with NVIC and VTOR, allow for relocation at startup of the interrupt vector table. Allow for dynamic IRQ handlers
Integration for peripheral specific pointers when in need of post interrupt execution.

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NVIC implemented inside micro::arm. Integrated with SYSTick. Next is SCB VTOR relocation, which still needs some research. Maybe reserve the first 1 kB (0x400) for the remapping of the vector table. Allow remapping under dynamic-vtable feature.