Log FeedbackVectors for optimised code and show them in the code-panel.

Drive-by-fixes:
- Fix off-by-one in SourcePositionIteration, making sure we always show
  the last element
- Ensure we process all SourcePositions in SourcePositionIteration
- Fix first load error in script-panel
- Allow expanding all text with SHIFT-click

Bug: v8:10644
Change-Id: Ic40a36ea82f0dfa2386c3196f27ca6978cf23643
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3245931Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77567}