Rename Tracer/MeterFactory to Tracer/MeterRegistry

[bogdandrutu]

No description provided.

[arminru]

No description provided.

Where does this requirement originate from?

[bogdandrutu]

I like the names better than Factory. Main reason is that we do have an internal shared state between all Tracers that is owned by the Registry or Factory, usually factories do not share state with elements created.

I don't feel very strong but I do think it is a better name.

[arminru]

I'm perfectly fine with TracerRegistry and do agree with your considerations, I just didn't know where this issue originated from. Once open-telemetry/opentelemetry-specification#354 is merged we are free to name it either way, I'm all in for TracerRegistry then.

[carlosalberto]

+1 on having it as Registry.

[Oberon00]

In my python PR (open-telemetry/opentelemetry-python#301) I named it TracerSource because it does not keep track of the created tracers, so registry would be wrong.