[EPIC] Chat panel behavior

[yarikoptic]

Related PR https://github.com/sparkletown/sparkle/pull/1311 / 🔒 https://github.com/sparkletown/internal-sparkle-issues/issues/622 is augmenting chat panel to be pinnable (on big screens) which would indeed be nice. It seems to need more testing and mitigate some issues, but if resizing to be developed, quite likely it might better be on top of that PR? May be @soichih has a quick idea on how to add resizing capability?