MeterProvider::meter should not use &'static str

[tqwewe]

It seems like the MeterProvider::meter method takes &'static str's for name (as well as version and schema_url).
https://docs.rs/opentelemetry/latest/opentelemetry/metrics/trait.MeterProvider.html

In my case, the string I want to use is not 'static, and this means I cannot use it to create meters.

I see that the instrument builder methods take impl Into<String> for the names. Maybe the meter functions could take the same, or Cow<'static, str> directly (since it seems like thats whats stored in the InstrumentationLibrary)

[djc]

Cow<'static, str> probably makes sense, would you be able to send a PR?