[FIX] tests: Bypass useless drawGrid

A non negligeable part of the rendering process consists of computations before
drawing on the canvas. At runtime, drawgrid takes around 99% of the rendering
time with in details:

Model.drawgrid : 8.7 ms
getGridBoxes: 3.53 ms
GetHeaderOffset: 1.09 ms
getVisibleRect: 0.37 ms
getSheetViewVisibleCols: 0.13ms

Which sums to (3.53+1.09+0.37+0.13)/8.7  * .99 = 58.2% of the rendering time.

In the tests, we completely mock the canvas to not draw anything. Based on that,
we are left with the computations which are not used anyway.

Tests `npm run test -- --maxWorkers=2 components`

before: 1108 tests > 108 seconds

after:  1108 tests > 85.77 seconds

==> 20.5 % improvement

closes #2292

Task: 3254822
Signed-off-by: Lucas Lefèvre (lul) <[email protected]>

tests/test_helpers/helpers.ts

@@ -154,6 +154,7 @@ export async function mountComponent<Props extends { [key: string]: any }>(
   env: SpreadsheetChildEnv;
 }> {
   const model = optionalArgs.model || optionalArgs?.env?.model || new Model();
+  model.drawGrid = () => {};
   const env = makeTestEnv({ ...optionalArgs.env, model: model });
   const props = optionalArgs.props || ({} as Props);
   const app = new App(component, { props, env, test: true });