Show password when choosing disk encryption password

**Describe the bug**
A clear and concise description of what the bug is.
Lack of "show password" toggle when choosing a password for disk encryption during install

**To Reproduce**
Steps to reproduce the behavior:
1. Go to 'install system'
2. During disk encryption dialogue

**Expected behavior**
A clear and visible toggle to switch between hidden password text and visible password text when choosing the password for the disk encryption during install of system.

**Desktop (please complete the following information):**
- OS: Elementary 6 BETA installer

I hope i'm not double submitting something, this is my first "issue" submission!