refactor opportunities

[caver456]

Hopefully some of these will improve performance / reduce lag

• [ ] change more setStyleSheet calls to use statusAppearanceDict instead - especially in loops and other lag-prone areas:
  • [ ] fsMoreBlink
  • [ ] fsFilterBlink
  • [ ] fsCheck
  • [ ] updateTeamTimers
  • [ ] addTab
  • [ ] rebuildTeamHotkeys
• [ ] updateTeamTimers: only set help window style sheets if help window is open
• [ ] updateTeamTimers: all tab stylesheets are being set once per second! See about reducing this loop to as-needed
• [ ] showTeamTabsMoreButtonIfNeeded - since it always shows, this could be simplified or hardcoded rather than a function
• [ ] make the qtabbar a completely separate widget - see this solution - this is not just a refactor, but it is an optimization
• [ ] reduce looping when sidebar is visible (it calls getExtTeamName for every callsign once per second - see #715
• [ ] refactor during implementation of new team name rules - see #719