fix: sdk should add /v1/traces and /v1/metrics endpoints implicitly

[bachgarash]

This PR fixes #4412 which should add metric and trace endpoints implicitly. Current implementation is a bit untidy and not complying with other languages such as Golang. I am happy to discuss more if it is not clear.

OTel sdk general config https://opentelemetry.io/docs/languages/sdk-configuration/otlp-exporter/#otel_exporter_otlp_endpoint

Description

Fixes # (issue)

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Test A

Does This PR Require a Contrib Repo Change?

• Yes. - Link to PR:
• No.

Checklist:

• Followed the style guidelines of this project
• Changelogs have been updated
• Unit tests have been added
• Documentation has been updated

[herin049]

Not really sure if I understand the issue here. It looks like /v1/{{signal}} is already being appended to the OTEL_EXPORTER_OTLP_ENDPOINT endpoint if it is provided. I think the expectation here is that if the user populates OTEL_EXPORTER_OTLP_{{signal}}_ENDPOINT they are likely explicitly passing a full url and likely don't want /v1/{{signal}} appended to it. The spec doesn't seem to clarify this point, but it looks like the other implementations notably JavaScript and Golang both exhibit this behavior.