Allow hiding sensitive parameters in UI

It would be amazing, if there was an additional property for a `coder_parameter` called `sensitiv` (or similar).
This would hide the current value of the parameter if the workspace is viewed.
It should allow to overwrite the parameter, therefore show it when the user overwrites it, but again hides it when the user saves the change.

This would allow users to e.g. input API keys as parameters, but hide them after inserting them.