[Task](ui): switch in-built Modal button sequence

[franzheidl]

Task Description

Switch the sequence in which the in-built buttons are rendered in a Modal in a way so that the primary / confirming action is on the right.

Sub-tasks

• Make sure the Confirm button is rendered on the very right of the Modal footer, the Cancel button adjacent to Confirm to its left
• Update storybook stories with custom buttons (passed as children) accordingly to reflect that rule/convention (Modal/Custom Modal Footer, Modal/ModalFooter/Custom, etc.)
• Remove note on the UX docs Modals page re default primary action button positioning inconsistency

Additional Context
Updating UX documentation accordingly is covered in a separate ticket: #1484