Consider adopting scrollbar-gutter to position error indicator #2863
Description
🧹 Tech Debt
Some components (text area, chat input, maybe others) have custom logic attempting to position the error icon when error-visible is set. The goal of that logic is to keep the icon nicely positioned both when a vertical scrollbar appears and when it doesn't.
The browser API scroll-gutter was introduced somewhat recently across all browsers and should be able to solve this problem for us. We should evaluate adopting it to remove the custom code that we maintain.