Increase the target size of the cancel button

Problem/Motivation

As a followup to #3469283-8: Elements within tip dialog modals only use browser focus styles instead of the theme focus styles, the target size of the cancel button of a tour tip is not meeting the minimum requirement of 24 by 24 pixels necessary to meet SC2.5.8 https://www.w3.org/WAI/WCAG22/Understanding/target-size-minimum.html

Steps to reproduce

Proposed resolution

Add a padding to the cancel button. Finding the padding values was a bit of try and error since the close icon is actually a glyph.

Remaining tasks

User interface changes

API changes

Data model changes