Add "confirm password" text field and "show password" button on the register page

[theSaLi]

• what is this feature about?
  Add "confirm password" text field and "show password" button on the register page.
  Adding these two things can make registration less error-prone.

• potential affected files?
  \frontend\src\components\registerview\RegisterView.jsx

• are there some depending PR that is not approved yet?
  no

[theSaLi]

I assign this issue to myself.