chore: use jaeger-idl/proto-gen/api_v2

[javiermolinar]

This pr tries to fix a panic when jaegerremote is used along with the OTEL collector

panic: proto: duplicate enum registered: jaeger.api_v2.SamplingStrategyType
      goroutine 1 [running]:
      github.com/gogo/protobuf/proto.RegisterEnum(...)
       /races/vendor/github.com/gogo/protobuf/proto/properties.go:520
      github.com/jaegertracing/jaeger-idl/proto-gen/api_v2.init.4()
       /traces/vendor/github.com/jaegertracing/jaeger-idl/proto-gen/api_v2/sampling.pb.go:432 +0x219
      )

It also fixes the example by using the jaegerremotesampling extension instead of the deprecated remote_sampling

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: javiermolinar / name: Javi (3c93529, 3a93d4a, 70665ec)

[javiermolinar]

jaegertracing/jaeger#6494

[javiermolinar]

I've added a line in the changelog :)