amazonq: reported customization telemetry can be wrong

## Problem

See: https://github.com/aws/aws-toolkit-vscode/pull/5362#discussion_r1793594093. The current way of recording telemetry events that contain customization field can lead to wrong telemetry being recorded.

The current logic seems to be getting the active customization at the time of an event (e.g interact with message) and as explained in the linked comment, this can lead to wrong metrics when a customer selects a customization after a message has been received and goes back to interact with that message

## System details (run `AWS: About` and/or `Amazon Q: About`)

n/a

Start with the linked pull request discussion, especially discussion_r1793594093, and trace the telemetry event logic for Amazon Q interactions containing a customization field. Done means events for an earlier message retain the customization associated with that message rather than using the currently active customization.

Written by the indexing model from the issue text.