Test text takes correct width

[sandstone991]

jest-canvas-mock returns the number of characters instead of the actual computed length (please refer here).
We use measureText here to determine the text width

zagydraw/src/utils/canvas/generateElement.ts

Line 266 in 3bd065f

const width = ctx.measureText(lines[largestLineIndex]).width;

we need to mock this method here

zagydraw/src/tests/actions/text.test.tsx

Line 88 in 3bd065f

//todo mock text measuring function because right now the mock just returns the length of the text