Quick-fixes: delete parameter names

For unused parameters, GoLand highlights the parameter name and type if they both can be removed. If the type is used for implementing a method specification, then only the name is highlighted.

In the latter case, you can click the name and press &shortcut:ShowIntentionActions; to select between the following quick-fixes: Delete parameter names or Rename to _. The same behavior is provided for functions that are used as a function type.