[DataGrid] Improve ptBR locale

[aline-matos]

Add missing export translations.

[oliviertassinari]

How about we use this opportunity to add the same keys commented in the other locales?

https://github.com/mui-org/material-ui-x/blob/f5221ef2a1b4345c244cfc3704de67b39472e54a/packages/grid/_modules_/grid/constants/localeTextConstants.ts#L28-L31

It will make it easier for the other translators to handle.

[m4theushw]

@oliviertassinari Side note: the toolbarExportLabel key is not used. We could remove it from the other locales in another PR.

[oliviertassinari]

Side note: the toolbarExportLabel key is not used. We could remove it from the other locales in another PR.

@m4theushw Great 👁️ for the details! It was added in #1030, maybe it was refactored and forgot along the way. In this case, no need to translate it.

[oliviertassinari]

maybe it was refactored and forgot along the way. In this case, no need to translate it.

@m4theushw Actually, it depends, It looks like @DanailH added it so that a button can have a label if only the icon is visible.

https://github.com/mui-org/material-ui-x/blob/45093913e390b9c71b89a3debf76a58a46e68a2f/packages/grid/_modules_/grid/components/toolbar/GridToolbarDensitySelector.tsx#L99

👍 for a new issue/a follow-up to make this consistent between the different toolbar buttons.

I would personally argue that for the only icon use case, https://next.material-ui.com/system/screen-readers/#visually-hidden-elements has the potential to be more elegant. Less code, fewer translations. But If we want to make it work in a responsive way (hide the label on small screens), it might not fly.