Auto-suggestion debounce/speed

## Problem
The speed that the auto-suggestion tries to pop in it's suggestions is extremely obnoxious. I DO appreceate it and would love to run it all the time, but it popping while I am writing code is constantly derailing me to the point that I need to manually pause/unpause it.

I basically had to revert to using the inline chat.

It would be extremely helpful to add a debounce that I can set the delay manually. Like, gimme 5-10 seconds after the last keystroke before popping suggestions?

This will also save you (amazon) money, as you will have less ignored suggestions.

## Expected behavior
5-10 seconds (prefer manually set) time before the auto-suggestion makes an attempt

In aws/aws-toolkit-vscode, start by locating the auto-suggestion trigger and any existing settings for its timing. Trace how keystrokes lead to a suggestion attempt, then identify relevant tests or entry points; done means suggestions wait for a configurable delay of roughly 5–10 seconds after the last keystroke.

Written by the indexing model from the issue text.