Toggle command for per_value_codelens

It would have been really nice to have the ability to toggle the code lens feature on/off in vscode currently I'm manually flipping the config setting on and off and that is a bit tedious.

Sometimes you want to see the types of everything to be able to verify that everything is correct and what you expect and sometimes that gets to cluttered in the UI and you want to turn it of.

Having a vscode command for this would make it possible to have a hot key for it and toggle the lens on and off.

Start by locating the existing per_value_codelens configuration and the VS Code command registration. Check how the command can toggle that setting and verify that the code lens visibility changes in VS Code; done means users can bind the command to a hotkey and switch the lens on or off.

Written by the indexing model from the issue text.