Onboarding: Rename wallet step improvements

[Hermez-cz]

At the end of the onboarding, when renaming the device:

• After entering the edit mode (by clicking the [Edit name] button),
  • Rename the [Edit name] button to [Save name]
  • Instead of the default name being a placeholder, please make it pre-filled input content and all of it selected and in focus
    • That means when user starts typing right away, the content will be replaced by theirs
    • If they click into the content or use arrow keys, they will be able to edit the content
  • Save the new name even when clicking the [Access Suite –>] button
  • Add 'esc' keyboard button functionality to close the input without saving

Please mind feasibility. If it would be effort-heavy, let's at least do the bold one ☝️ and discuss the rest.

Current implementation: