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

* Add a manifest generator for draft-ietf-03

* Remove files from the previous versions of the tool

* Move draft-ietf-suit-manifest-03 files to root

* Move examples to examples folder

* Add reference material to the README

Added an example manifest in CBOR and in CBOR diagnostic Notation

Adding the CDDL as specified in https://tools.ietf.org/id/draft-moran-suit-manifest-03.html#rfc.section.8

Fix ID conditions in test1.json

Update generator to draft-moran-suit-manifest-03

Add a public key conversion function

Converts a ECDSA PEM public key to the format needed by libcose + mbedtls

Invoke with: 'ec_key_to_mbedtls_points.py pubkey.pem

Fix URI element array order

ed25519 signing and key pair generation support

Add usage examples to README
Several fixes to encode.py

This encoder has only basic functionality:
* Add version number
* Add text fields
* Add nonce
* Add timestamp (monotonic sequence number)
* Add conditions
* Add directives
* Encode into CBOR

Missing features:
* Aliases
* Dependencies
* Extensions
* Payload Info
* Write to file
* Sign
* Create COSE structure.