Massive refactor to accommodate RISC-V targets

- Refactored entire codebase (excluding the Insight component) to accommodate multiple target architectures (no longer specific to AVR)
- Deleted 'generate SVD' GDB monitor command - I will eventually move this functionality to the Bloom website
- Added unit size property to address spaces
- Many other changes which I couldn't be bothered to describe here

build/scripts/Targets/TargetDescriptionFiles/Services/Xml/FromXmlService.php

@@ -116,6 +116,7 @@ class FromXmlService
             $attributes['key'] ?? null,
             $this->stringService->tryStringToInt($attributes['start'] ?? null),
             $this->stringService->tryStringToInt($attributes['size'] ?? null),
+            $this->stringService->tryStringToInt($attributes['unit-size'] ?? null),
             $attributes['endianness'] ?? null,
         );