This chang creates a GaugeInfo metrics type for registering informational (textual) metrics, e.g. geth version number. It also improves the testing for backend-exporters, and uses a shared subpackage in 'internal' to provide sample datasets and ordered registry.
Implements #21783
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Co-authored-by: Martin Holst Swende <martin@swende.se>
* metrics: zero temp variable in updateMeter
Previously the temp variable was not updated properly after summing it to count.
This meant we had astronomically high metrics, now we zero out the temp whenever we
sum it onto the snapshot count
* metrics: move temp variable to be aligned, unit tests
Moves the temp variable in MeterSnapshot to be 64-bit aligned because of the atomic bug.
Adds a unit test, that catches the previous bug.
