Bug 2012475 - Spike - Backfill/Retriggers directly from the graphs

[esanuandra]

This is a POC for backfill/retrigger directly from graphs view tooltip

Main implementation is in GraphsView.jsx and GraphTooltip.jsx, rest of the files are path update.

[florinbilt]

The code looks good and works as expected, nice work reusing the shared models and moving the stores/Notifications into shared. Since this is a spike, none of the below should block the PR, but I'd like to file them as follow-ups:

1. Two notification systems now coexist in perfherder: the existing inline one (ErrorMessages/ValidationGate) and the toast store imported here (notify/useNotificationStore). We should standardize on one. While at it, the clearExpiredNotifications interval and the CSS import are now copy-pasted in both App.jsx and GraphsView.jsx, better encapsulated in the Notifications component.

2. Extract a shared backfill/retrigger helper: GraphTooltip.backfillJob duplicates ActionBar.backfillJob. It can't be imported directly (the latter is a class method reading this.props), so the fix is a shared helper both views call. This would also let us align a small inconsistency between the two new actions (retrigger fetches its decision-task map via JobModel, backfill does it manually).