✨ Expose reporting config to consumers of `javaagent-core` so that `Filter` implementation authors can access them

[ryandens]

Description

Allow the HypertraceConfig APIs around reporting and OPA configuration to be exposed to clients following a similar pattern as done with the InstrumentationConfig. PR #322 moved the config implementation out of the javaagent-core package, but some implementations of the Hypertrace Filter API need to access config properties that are not accessible via the InstrumentationConfig object. As this is a public API, I wanted to make it well known that the ReportingConfig.Opa object isn't going to live forever in this repo, as we'd like to eventually remove configuraton options that are intended for use by Traceable to not be included in the Hypertrace repo.

Testing

Please describe the tests that you ran to verify your changes. Please summarize what did you test and what needs to be tested e.g. deployed and tested helm chart locally.

Checklist:

• [x] My changes generate no new warnings
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] Any dependent changes have been merged and published in downstream modules

Documentation

Make sure that you have documented corresponding changes in this repository or hypertrace docs repo if required.

N/A

[ryandens]

@pavolloffay I know you have lots of context and perspective on this (re: #322 ) let me know if you have any concerns/feedback!

[pavolloffay]

Yeah this PR should not be needed as the https://github.com/hypertrace/javaagent/blob/main/otel-extensions/src/main/java/org/hypertrace/agent/otel/extensions/config/HypertraceConfig.java is available when the filter is created.