Fix rest-cxf-opentelemetry example: use CamelCxfOperationName, migrate to camel-opentelemetry2

[Croway]

Summary

Same underlying bug as #206 (rest-cxf), replicated across all 3 services in this example:

• random, even, and odd CamelRouters each dispatched on ${header.operationName}, a header CXF-RS never sets. DefaultCxfRsBinding actually populates CamelCxfOperationName for every cxfrs request regardless of binding style, so the header resolved empty and every REST call hit bean:...ServiceImpl?method= with a blank method name, throwing MethodNotFoundException (500).
• Fixed by routing on ${header.CamelCxfOperationName} in all three modules (kept the existing toD dispatch style already used here, consistent with Fix rest-cxf example: use CamelCxfOperationName for dynamic bean dispatch #206).

Additionally, camel-opentelemetry (v1) logs a deprecation warning suggesting camel-opentelemetry2. Migrated all 3 services:

• Swapped camel-opentelemetry-starter → camel-opentelemetry2-starter in rest-cxf-opentelemetry/pom.xml.
• Swapped @CamelOpenTelemetry → @CamelOpenTelemetry2 (and the corresponding import) in each service's Application class.
• This matches the convention already used by the sibling opentelemetry/*Booking examples in this repo, which are already on camel-opentelemetry2-starter.

The OTel javaagent (2.19.0) attaches fine on JDK 25 here, confirmed while testing.

Test plan

• mvn -pl rest-cxf-opentelemetry,rest-cxf-opentelemetry/rest-cxf-otel-common,rest-cxf-opentelemetry/rest-cxf-otel-random,rest-cxf-opentelemetry/rest-cxf-otel-even,rest-cxf-opentelemetry/rest-cxf-otel-odd -am package
• Built the OTel javaagent via -Potel-agent, started docker-compose (minio, otel-collector, jaeger), pre-created the evenodd minio bucket, and ran all 3 services (random:8080, even:8081, odd:8082) with the javaagent attached
• POST /services/api/play/5 on random → 200, correct even/odd split result (exercises the full random → even/odd → register → minio round trip)
• POST /services/api/check on even and odd directly → 200
• GET /services/api/generate on random → 200
• Logs confirm Opentelemetry2 enabled, no deprecation warning, no exceptions

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