[8.19] (backport #8753) EDOT collector: include the forward connector.

[mergify]

• Relates [Fleet] Support input packages with OTel configuration kibana#224472
• Relates New httpcheck package based on the Otel collector httpcheck receiver integrations#14315

https://github.com/open-telemetry/opentelemetry-collector/tree/main/connector/forwardconnector

Include the forwardconnector, which we are highly likely to need for OTel native integrations to allow for unique processors per receiver without having to have unique pipelines with duplicate exporters.

To test this PR I used the following configuration showing how to have 2 filelog receivers that could have separate processors applied but export via the same exporter.

receivers:
  filelog:
    include: [ /var/log/system.log ]
    start_at: beginning
  filelog/2:
    include: [ /var/log/wifi.log ]
    start_at: beginning

processors:
  resource:
    attributes:
    - key: service.name
      action: insert
      value: elastic-otel-test

exporters:
  debug:
    verbosity: detailed
    sampling_initial: 10000
    sampling_thereafter: 10000

connectors:
  forward:

extensions:
  memory_limiter:
    check_interval: 1s
    limit_mib: 700
    spike_limit_mib: 180
  health_check:
    endpoint: "localhost:13133"
    path: "/health/status"

service:
  extensions: [health_check, memory_limiter]
  pipelines:
    logs/system:
      receivers: [filelog]
      processors: [resource]
      exporters: [forward]
    logs/wifi:
      receivers: [filelog/2]
      processors: [resource]
      exporters: [forward]
    logs/export:
      receivers: [forward]
      exporters: [debug]

---

This is an automatic backport of pull request #8753 done by [Mergify](https://mergify.com).

[elasticmachine]

Pinging @elastic/elastic-agent-control-plane (Team:Elastic-Agent-Control-Plane)

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube