[CLI] Improved error messages in case of missing commas or brackets

Sometimes I’m missing a “,” like here after members & admins while creating/editing a .fsl file:

org!.update({
        roles: {
          members: org!.roles.members.filter(member => member != successor || member != user) 
          admins: org!.roles.admins.filter(admin => admin != successor || member != user)
          owner: successor!
        }
      }

Or I missed adding enough closing brackets:

if( data?.successorId != null && User.byId(data!.successorId) 

currently this leads to the general error

error: Expected a function definition

which is quite time consuming to debug.

It would be great to have some narrowed error messaging like L19 "," expected

Version: CLI v4