telemetry(inline-suggestion): fine tune supplemental context strategy telemetry

[Will-ShaoHua]

Problem

Current supplementalContextStrategy only reflect what group the user is in, however by doing this it won't help much on our data analysis. What we need is the context strategy being used so that we know how much % of users have repomap or opentabs and how % of users have empty supplemental context etc.

Solution

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• Treat all work as PUBLIC. Private feature/x branches will not be squash-merged at release time.
• Your code changes must meet the guidelines in CONTRIBUTING.md.

License: I confirm that my contribution is made under the terms of the Apache 2.0 license.

[github-actions]

• This pull request modifies code in src/* but no tests were added/updated.
  • Confirm whether tests should be added or ensure the PR description explains why tests are not required.

[Will-ShaoHua]

there are a lot of undesired duplicate code within this function, planing to use #6168 to resolve this as a followup and it will requires more testing.