Add Password manager UI as an extension of the k/v commandline storage

Using k/v store would be a perfect usecase to use it as a password manager.

Adding the following capabilities to the UI would make it easier to use it for such usecases.

- Tab `Credentials/Secrets`
- Capability to manage keys and values from UI
- Capability to copy the value to the clipboard
- Capability to copy the key to the clipboard

On a Laptop I can still use the terminal to access the k/v pairs, however on a mobile device I now don't have an option to read the values.

What do you guys think of this idea?

Start by tracing the existing k/v commandline storage and the mobile UI entry point. Define how the Credentials/Secrets tab should manage keys and values and how copying either field to the clipboard should work. Done means the mobile UI supports those listed capabilities for k/v pairs.

Written by the indexing model from the issue text.