Add support for native histograms in OM parser
This PR adds an OM parser for native histograms, as a first step towards the implementation of the following proposal https://github.com/prometheus/proposals/pull/32 . The next steps (as far as this repo is concerned) would be the OM exposition and then obviously the implementation of native histograms generation/writing logic.
Just a quick read through, but I was thinking maybe we limit the changes in the initial PR to just the parser changes? We could get that in and start iterating on it, and it will then be useful for testing the exposition changes.
I totally agree!
Thanks for the suggested changes, I'll be working on it :)