Remove dependency on cmd/agent from OTEL Collector contrib

[yurishkuro]

Part of #6408

OTEL collector contrib has these dependencies:

receiver/jaegerreceiver/jaeger_agent_test.go
16:	"github.com/jaegertracing/jaeger/cmd/agent/app/servers/thriftudp"
17:	jaegerconvert "github.com/jaegertracing/jaeger/model/converter/thrift/jaeger"

receiver/jaegerreceiver/trace_receiver.go
23:	"github.com/jaegertracing/jaeger/cmd/agent/app/processors"
24:	"github.com/jaegertracing/jaeger/cmd/agent/app/servers"
25:	"github.com/jaegertracing/jaeger/cmd/agent/app/servers/thriftudp"
26:	"github.com/jaegertracing/jaeger/pkg/metrics"

• Copy the code into OTEL and remove the dependency [receiver/jaeger] Remove dependency on jaeger/cmd/agent open-telemetry/opentelemetry-collector-contrib#38655
• One remaining indirect dependency in contrib via Dependency on deprecated github.com/jaegertracing/jaeger/model signalfx/sapm-proto#227, but non-blocking for us since we don't import those modules
• Remove cmd/agent from Jaeger 🎉 🎉 🎉 (deprecation) Remove jaeger-agent #4739

[danish9039]

WORKING ON IT

[AdityaS8804]

Hey,
I made the appropriate changes to OTEL-Collector-Contrib in this PR : OTEL PR Raised
Once this is approved, I can remove cmd/agent and push the code to jaeger