Support localStorage api

[anbraten]

Is your feature request related to a problem? Please describe.

It would be pretty cool to have sth like localStorage to store simple key-values in the context of a function. I used this quite often in node-red to store simple states for example used to create singeltons with a timestamp lock.

Describe the solution you'd like

Support for localStorage similar to the browser implementation. The localStorage should use the function as context so only a function can access the data.

Describe alternatives you've considered

I could use an external database / key-value api.