Code enhancement: Use the KNX lib for Datapoint parsing

[petero-dk]

Right now the app uses its own simple datapoint parsing in: https://github.com/athombv/org.knx/blob/master/lib/DatapointTypeParser.js

However the knx lib actually have a very robust and detailed parsing library that is also extendable, I have used those methods for the receive telegram flow: https://github.com/athombv/org.knx/pull/21/files#diff-e07d531ac040ce3f40e0ce632ac2a059d7cd60f20e61f78268ac3be015b3b28fR58-R59

A first step would be to simply make DatapointTypeParser use that implementation instead of its own implementation, so we leverage any bug fixes in the upstream library.

What do you think?

[ttherbrink]

Personally i think that if there are no bug with the parser at the moment we should leave it be. It allows us to create quicker fixes than waiting for a library to merge our fix.
If there are any significant improvements in using the KNX lib parser i am open to discussion on that matter.

[petero-dk]

I will not touch it for now, it was just an observation.