Save passwords as sensitive values

[janepie]

Describe the bug

Passwords saved via Declarative Settings should be saved as sensitive values (encrypted) and not exposed to the frontend again.

Steps/Code to Reproduce

Use declarative settings to set a password and

• check the db value and see it's unencrypted
• reload the page and see that the placeholder dots match the password length

Expected Results

• encrypted value in db
• no exposing of the password again

Actual Results

• unencrypted value in db
• password exposed to frontend

Setup configuration

nc_py_api=0.19.2

[bigcat88]

This will be supported starting from Nextcloud 32