Change DevconID to String in ASX / ASN and resulting JavaScript

[SmartLayer]

Change DevconID to String is solved on the issuer side in #118. Follow that change

[darakhbharat]

Hi @colourful-land,

I have implemented the change in the branch DevconIDToString, similarly I have updated the autogenereation script and incorporated the related changes (DevconID to String) in my development branch asn1js-parser-serializer(#108).

I can create the pull request from required branch as you suggest. My dev branch asn1js-parser-serializer has some work in progress changes but we can create the draft PR if you suggest.