Ability to add custom passwords onto saved credentials

[John_Llama]

So I noticed with some things that you can add a “Master password re-prompt”, and noticed that there isnt a way to set a custom password on a password, because if someone has access to your bitwarden account, they’d most likely know the master password and hence makes Master password almost entirely useless, so I am asking for there is the ability to set a custom password on already saved passwords/cards ect, I would love for this to be a feature as it would add a layer of security