[ic-status-tag]: Add uppercase prop on status tag

[GCHQ-Developer-112]

Summary

Add uppercase prop on IcStatusTag so users have the option to not have an uppercase label

💰 User value

Overall, research has shown that uppercase can be hard to read however there are cases where using uppercase can show the importance of a piece of text especially when use for texts of only a few words. To allow for both sides of the argument, an uppercase prop should be introduced on status tag to allow users to "turn off" the use of uppercase in status tag.

Research:

• All-Caps Headings: Are They Bad for Accessibility?
• Design for readability
• Typography for Glanceable Reading: Bigger Is Better (NN group)
• Don’t use all caps. A case study (Accessible by Design)