MeterProvider support for adding multiple Meter sources with wildcard support.

[cijothomas]

Similar to Traces
https://github.com/open-telemetry/opentelemetry-dotnet/blob/main/src/OpenTelemetry/Trace/TracerProviderSdk.cs#L161

[Yun-Ting]

I will be working on this issue.

[mic-max]

Looks like the Trace wildcard mode has a bug

opentelemetry-dotnet/src/OpenTelemetry/Trace/TracerProviderSdk.cs

Line 169 in 15981df

// Validation of source name is already done in builder.

wildcardMode is only set based on the last name in the sources containing a "*" rather than any of them containing that character.
What are the projects thoughts on using Linq? I have heard that the performance is not as good but in cases like this writing something like this would be more understandable to me:

var wildcardMode = sources.Any(name => name.Contains("*"));

[cijothomas]

Could you describe why you believe there is a bug? wildCardMode is set to true, if any source has *, not just the last one... (Though I think we can break out, if wildCardMode is once set to true..)

[mic-max]

My bad, yes you're right. Yes breaking out here would give us the same result 🙂