The code which copies DecReports to host should respect the version number of the data it is given

The following discussion from !911 (merged) should be addressed:

• @graven started a discussion: (+1 comment)

  Note that the code 'as-was' blindly assumed a v2 dec reports raw bank -- so even though I changed the version in DecReporter.cu to actually make a v3 bank, this code then took the payload, and than added it to the raw event proclaiming it to be a v2 bank, which the decoder subsequently had a hard time to interpret...

  For the time being, I'm just going to hardwire v3, but this behavior is quite error-prone. There should be, as the comment above says, a single source of information, and it should be propagated consistently.