Use easycaching with elastic apm agent dotnet

# Description

Hi, I want to use [elastic/apm-agent-dotnet](https://github.com/elastic/apm-agent-dotnet) to trace the commands sent to Redis.
Here is a sample code from elastic official document:

```csharp
// using Elastic.Apm.StackExchange.Redis;

var connection = await ConnectionMultiplexer.ConnectAsync("");
connection.UseElasticApm();
```

Do I have any chance to get the connection from easycaching or provide a delegate to easycaching?

# References

- https://www.elastic.co/guide/en/apm/agent/dotnet/1.x/setup-stackexchange-redis.html