fix(chat): disable smooth scroll to bottom

[Antreesy]

☑️ Resolves

• disable smooth scroll to bottom
• update previous scroll position in scroll event (not after it's finished)
• store direction while scrolling
• ensure debounceHandleScroll is fired before endScroll

• Fix "Scroll to bottom" does not scroll all the way #13237

🖌️ UI Checklist

🖼️ Screenshots / Screencasts

🏚️ Before	🏡 After

🏁 Checklist

• 🌏 Tested with different browsers / clients:
  • Chromium (Chrome / Edge / Opera / Brave)
  • Firefox
  • Safari
  • Talk Desktop
  • Not risky to browser differences / client
• 🖌️ Design was reviewed, approved or inspired by the design team

[Antreesy]

I know that smooth: false is default, just not sure if we keep it or bring back later, so want to explicit that it's disabled

[DorraJaouad]

Please state the reason why we disable smooth scroll to bottom so we would be aware of any issues :p.

[nickvergessen]

Please state the reason why we disable smooth scroll to bottom so we would be aware of any issues :p.

Can even link to the original issue or PR, so you have the reference videos :)

[DorraJaouad]

Can even link to the original issue or PR, so you have the reference videos :)

Still not evident that it fixes this issue 100%, it increased the speed of down scrolling so the widget scrolling workaround and the down scrolling will unlikely overlap.

[Antreesy]

widget scrolling workaround

Still going to work with user wheel-scrolling

why we disable smooth scroll

• Less load on client to draw animation frames
• Skip observer checks for widgets (if they're working), so we don't trigger their render