Refactor/mpu manager

[FoniksFox]

Refactor of the MPU so that it works with the new compile-infrastructure.

You can inscribe any type, on any memory domain, with any alignment (up to 32B, since there's no meaning in going any further) cacheable or non-cacheable. The MPU module will calculate and allocate on compile-time all the memory required with the required offsets and everything, such that it even fails if you request too much memory (well, the linker script is the one that actually fails).

It still gives support to the legacy MPUManager.

It has a greater range of protection of the memory, so that you cannot access any memory that is not explicitly defined as accessible.

It dinamycally (in linking-time) allocates the necessary memory with the minimum padding possible so as to not waste any unnecessary memory.

The linker script has been changed to adapt to this new structure.

You need to delete the MPUManager::start() call from Runes to make this work (since this function no longer exists).

Other changes made in the Linker Script include:

• Use DTCM (Data Tightly Coupled Memory) for Stack, Heap and Static
• Allow the use of ITCM (Instruction Tightly Coupled Memory) by declaring a function as RAM_CODE (better performance)
• Allow access to any memory region by either using an attribute or by requesting it to the MPU driver
• Optimize MPU settings for better performance
• Use Linker Script as only source of truth for the memory region start addresses and sizes
• Move some symbols that had questionable placement to the new system

[StefanCostea]

Minor changes suggested, but overall looks very good, I would focus in merging this quicklu

[Cantonplas]

LGTM