Compare floats with margin of error to avoid infinite recurrence

[eszpotanski]

Chromium-based browsers can report slightly different widths and heights for divs covering the same area, based on used zoom.

For instance, when Speedscope is used with 110% zoom and window size is changed (or redraw is triggered in some other way), the following error is raised, sometimes preventing blocks from being redrawn (the same as in #486):

canvas-context.ts:56 Uncaught RangeError: Maximum call stack size exceeded
    at CanvasContext.onBeforeFrame (canvas-context.ts:56:27)
    at graphics.ts:497:46
    at Set.forEach (<anonymous>)
    at Context.resize (graphics.ts:497:32)
    at GLCanvas.maybeResize (application.tsx:107:33)
    at CanvasContext.onBeforeFrame (canvas-context.ts:63:7)
    at graphics.ts:497:46
    at Set.forEach (<anonymous>)
    at Context.resize (graphics.ts:497:32)
    at GLCanvas.maybeResize (application.tsx:107:33)

In this PR, a small margin of error is introduced to make sure the recurrence is properly stopped. It potentially fixes #418 and #486.

[coveralls]

coverage: 43.454%. remained the same
when pulling 20b47e1 on antmicro:eszp/fix-infinite-recurrence-when-redrawing
into fc76932 on jlfwong:main.

[jlfwong]

Amazing, thanks for tracking down the root cause of this!

[jlfwong]

@eszpotanski This is now live on https://speedscope.app and published to npm as [email protected]