Also add tests, makefile for parser

Remove mbed files

Correct generation of manifest, specifically digests.
Add reporting policy to SUIT parser.

Default was 1k, which was too small for hss-lms

Also remove unused "choice" extension.
Reduces size by 12

More verbose, but 6 bytes smaller.

All CBOR integers are handled in 64-bit in this library. Because of this, they must be down-cast before use. Some unnecessary 64-bit integer handling was left over. Removing this saves 64 bytes, bringing the parser to 1976 bytes

This is a large refactor that makes the code flow much simpler. The parser still needs better debugging infrastructure.

* Unimplemented variables are no longer used
* Tags are now handled
* bstr wrappers are now handled implicitly where necessary
* Added a new k/v pair handler that processes a key with a type in one shot.
* Added distinct handling for arrays (a sequence of identical types) and lists (a sequence of different types)
* Integrated COSE signature handling
* Added a const array initializer helper macro so that parser element counts are calculated at compile-time.
* Added an image verification handler that consumes SUIT_Digests and handles the algorithm correctly
* Verify manifest against authenticated hash before processing

Add an example bootloader and application that use the SUIT manifest.