Safe Principal methods #323
Description
Given recent forum feedback and our internal messages/requests there seems to be the need for safe Principal methods that don't trap.
Current methods that trap:
Principal.fromText(t : Text) : PrincipalPrincipal.fromBlob(b : Blob) : Principal
Add safe alternatives that validate the input and return ?Principal.
Current workaround is to use principal-ext mops package which offers a safe fromText method.