Reworked Jcampdx : simplification and remove try-catch

[aTrotier]

I saw on youtube that try-catch is especially not optimized in Julia : https://www.youtube.com/watch?v=-kjFKnEsZRU

The JCAMPDX read function is complex (thanks to bruker that does not rely on a standard format...) but I suppose it is possible to make something more maintainable :)