Proposed title of this feature request

Allow customized otlp URL endpoint for ClusterLogForwarder 

What is the nature and description of the request?

The vector logforwarder in our OpenShift should be configurable to send data to an external otlp endpoint which doesn't follow the strict and expected syntax for the endpoint /v1/logs.

oc explain clusterlogforwarder.spec.outputs.otlp.url
GROUP:      observability.openshift.io
KIND:       ClusterLogForwarder
VERSION:    v1

FIELD: url <string>


DESCRIPTION:
    URL to send log records to.
    
    An absolute URL, with a valid http scheme. Must terminate with `/v1/logs`
    
    Basic TLS is enabled if the URL scheme requires it (for example 'https').
    The 'username@password' part of `url` is ignore 

We need the flexibility to configure the endpoint in the ClusterLogForwarder by our needs.The OTLP/HTTP Request spec suggests the `/v1/logs` as a default path but not as a hard requirement.

The default URL path for requests that carry log data is /v1/logs and the request body is a Protobuf-encoded ExportLogsServiceRequest message.

Many logging system receivers allow the configuration of the otlp endpoint. Which in turn means OpenShift cannot work with logging solutions built to receive this data.

Why does the customer need this? (List the business requirements)

External log management and analysis tool (LogScale) in place. LogScale requires the otlp endoint to be `${HOST}:${PORT}/api/v1/ingest/otlp`, see further LogScale docs.

All logs from all applications and infrastructure (not only OCP) should be sent into this tool. It's used for security reporting, monitoring and log management as well. OpenShift does not offer the required flexibility.

This is not only a LogScale topic, because each system which does not force you to the `/v1/logs` endpoint will be incompatible with OpenShift for the OTLP protocol. The only system which forces you to use `/v1/logs` is Elasticsearch as far as we can tell, see Elastic docs.

List any affected packages or components.

OpenShift Logging ClusterLogForwarder and OpenTelemetry output