fix: telemetry for agentic chat interactions

[chungjac]

• For context, here is the agentic-chat branch PR which I am porting over to language-servers: telemetry(chat): agentic chat metrics aws-toolkit-vscode#6979

Problem

• We would like metrics based on these product requirement definitions:
  1. Command execution acceptance rate:
     • [#Commands that users click run on] / [#Commands generated that required user to click run on]
  2. Diff acceptance rate:
     • As all diffs are auto-accepted, the acceptance rate is calculated by: 1 - [#Diffs rejected] / [#Diffs generated]
     • Rejection is defined as user specifically pressing the Undo button
  3. Stop chat:
     • User specifically clicks Stop button
     • Implicit stop: user interrupts current ongoing message with new message

Solution

• emit amazonq_interactWithAgenticChat metric

Testing

• tested in kibana

License

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.