Make the inspector tab responds accordingly when the user clicks at the Visual Script's members

**Describe the project you are working on:**
I'm working on a 3D endless runner game.

**Describe the problem or limitation you are having in your project:**
The project's code is quite complex than I originally thought. Therefore as the project grows, there are a lot of functions that I want to add more arguments, and a lot of variables that I want to modify their default value or adding some hints.

However, I can't do that with efficiency due to the fact that the inspector tab is not responded to the members at all. Therefore if I want to edit the function's arguments, I will have to:

1. Double click at their name in the members' window to go to the function node.
2. Click at the function node to make changes in the inspector tab.

That's the unnecessary steps if I could just click at the function in the members' window and modify it in the inspector tab right away.

It's even worse with the variable's situation regarding this issue, as in order to edit the default value, change their data type, or add some hints, etc., I will have to:

1. Click or right-click on their name in the members' window.
2. Hit ctrl+e or click on the menu, depending on the 1st step, to open the variable's small and cramped edit window.

That's the unnecessary steps and moreover, editing the variable in the inspector tab which has a much bigger space to work with and also resizable would be a lot more intuitive as far as UX goes.

**Describe the feature / enhancement and how it helps to overcome the problem or limitation:**
The feature I am proposing will definitely make the Visual Script's workflow a lot better than it currently is, as this enhancement reduces the required steps for the same task and it also doesn't break any current implementation due to little changes in the editor's current behaviors.

Currently, the inspector tab just doing nothing while eating the screen space when the user interacts with various functions or variables in the members' window.

**EDIT:** Adding an obvious benefit of this enhancement which I forgot to mention earlier. It would be a lot easier to fast peek at the function's arguments, and especially the variable's values of the array and dictionary data type in the inspector tab than anywhere else in the editor.

**Describe how your proposal will work, with code, pseudocode, mockups, and/or diagrams:**
Make the inspector tab responds accordingly when the user clicks at the Visual Script's members.

**If this enhancement will not be used often, can it be worked around with a few lines of script?:**
This enhancement will be used all the time and it can't be worked around with a few lines of script as it's the core feature of the engine.

**Is there a reason why this should be core and not an add-on in the asset library?:**
This is the core functionality.