fix(css): update stateful and responsive mixins naming pattern

What does this MR do?

BREAKING CHANGE: Stateful and responsive mixins naming patterns have been updated so that they always start with the gl- prefix, followed by the state or breakpoint.

Make sure to update your utility class usages to reflect those changes.

For example:

- <div class="hover-gl-rounded-base">
+ <div class="gl-hover-rounded-base">

Does this MR meet the acceptance criteria?

Conformity

• Code review guidelines.
• GitLab UI's contributing guidlines.
• If it changes a Pajamas-compliant component's look & feel, the MR has been reviewed by a UX designer.
• If it changes GitLab UI's documentation guidelines, the MR has been reviewed by a Technical Writer.
• If the MR changes a component's API, integration MR(s) have been opened in the following projects to ensure that the @gitlab/ui package can be upgraded quickly after the changes are released:
  • GitLab: mr_url
  • Customers Portal: mr_url
  • Status Page: mr_url
• Added the ~"component:*" label(s) if applicable.