data-grid: changes display from 'flex' to 'grid', and removes flex-direction

[joacoc]

Link to relevant issue

This pull request resolves #473

Description of changes

This PR modifies the style of vscode-data-grid by changing the display property from flex to grid and removing the flex-direction property.

Component gallery test screenshot

[hawkticehurst]

Thanks for the PR @joacoc! 😊

As I just discussed in the related issue thread I'm actually unsure if this fixes the problems that are described in #473 (or at least I was unable to produce a solution with the changes you provided).

Could you describe a bit more of what issue(s) you were facing and how the changes in this PR fixed your issue?

[hawkticehurst]

Going to go ahead and close this PR since the toolkit is going to be deprecated by the end of the year (more info at #561). Thanks again for trying to help out on this one :)