Reduce re-rendering by disabling animation in blame info in the status bar

[gdh1995]

Currently behavior

1. Currently Gitlens shows blame information in the status bar (controlled by gitlens.statusBar.*)
2. When I move caret to another line, it will update the blame information
3. When gitlens.statusBar.reduceFlicker is true by default, there's a "turning circle" before blame info before new info gets loaded

What I want

I want (a new setting item) to replace the circle animation with:

• either a "static icon" which means "updating"
• or keep the icon unchanged, and switch to another icon on further errors or timeout events

The benefits of this feature

Firstly, this means: further reduce flickers; easier to read; not attract attention in any sense.

Secondly, a static icon will save computer power a lot: during my tests using Developer Tools -> Render -> Paint flashing,

1. with the turning circle, moveing caret causes to render many UI parts

• 1. if a VS Code window is small, then many left icons flash
     
• 2. if a window is large, then there're a strange full-area rendering, like:
     

2. when reduceFlicker=false, there's no turning circle, and then
   

[eamodio]

I've changed this from a spinner to just a watch icon to reduce the visual noise. FYI, in the current insiders version of VS Code the re-rendering issue you are seeing above seems to be resolved whether a spinning icon is used or not.