[receiver/hostmetrics] remove direction attribute

[codeboten]

The following change adds the direction to the metric name, removing the direction attribute.

Fixes #11817

[dmitryax]

I think this receiver is stable enough to avoid making such breaking changes. I believe many distributions depend on it.

Can we make it through a feature gate (or enabling/disabling metrics) spanned across several versions in the following way?
0.55.0: keep reporting the old metrics with a warning that they will be replaced and provide a way to switch to the new metrics through a feature gate or disabling/enabling metrics.
0.57.0: switch to the new metrics with an option to bring the old metrics back.
0.59.0: remove old metrics.

[codeboten]

reporting the old metrics with a warning

Would this warning show up at collector start?

[dmitryax]

Would this warning show up at collector start?

Yes, we've done this many times for such breaking changes

[codeboten]

Would this warning show up at collector start?

Yes, we've done this many times for such breaking changes

@dmitryax it's behind a feature gate now, please take a look

[dmitryax]

Overal LGTM

[sweetpotato0]

i have a quetion: why set the some metric to Deprecated, such as system.network.dropped、system.network.errors

[dmitryax]

@sweetpotato0 thanks for pointing to this. The deprecated labels should've been removed some time ago. I submitted #16227 to fix it