[Combo button] Button title to be updated as "Primary action" instead of "Actions"

[alina-jacob]

Problem:

The combo button has two buttons, primary and icon-only primary button. The primary button should have a title "Primary action"
Currently the Figma component has the button title as "Actions"

Solution:

• Update the button text from "Actions" to "Primary action" for all sizes and alignment
• Figma and Carbon review