feat(feature-flags): add agentless configuration keys, settings, and endpoint derivation - #9040

• All applicable commits are signed and verified
  _{Digest: 0312635}

• All required reviewers must approve this pull request before it can be merged. Learn more in our FAQ.

• Needs approval from Team: tracing-dotnet

• Needs approval from Team: feature-flagging-and-experimentation-sdk

• Needs approval from Team: apm-dotnet

  _{Questions about this check? Reach out in #dx-source-code-management on Slack.
  Digest: 1579a36}

• All applicable files are owned properly
  _{Digest: 1e33ec2}

if this seems incorrect, you can retrigger the evaluation of the MergeGate by clicking on this link