Text in the flame chart should be sticky when it is partly off the left side of the screen

[jacob314]

This will make it easier to read flame chart entries that are partly off the side of the window..
I have some ideas for how we can efficiently achieve the effect using the existing code. We used to achieve it with CSS but we lost the functionality when we switched to more efficient straight to canvas rendering.

Fyi @kenzieschmoll

[kenzieschmoll]

This issue is still relevant in the flutter web aop