Minor UI Fixes for Settings Page

Requested changes are marked in #3750.

Purple help text is currently under "Data Classification" heading, when it should be under the "Settings" heading
Help text in incorrect it should read "These settings can only be changed before publishing." "Ces paramètres ne peuvent être modifiés qu’avant la publication."
Spacing is inconsistent and too cramped between each section: Data classification, Response delivery option, Purpose and use. Ensure there is a class of "mb-10" between each section.
text correction: Response delivery option should be "Delivery option" "Option de livraison"
text correction: "Retrieve responses within 45 days." should be "GC Forms holds data temporarily for 30 days." "Formulaires GC conserve les données temporairement pour 30 hours."
Bold the line "Help us understand how form responses will be used"
Alignment of bullets "Personal information used to make a decision about an individual" and hint text is misaligned, try class "ml-12"

cds-snc / platform-forms-client