Rework variable tracker module

[worron]

First of all, thank you for sharing your work, this tool is amazing. Unfortunately my project has a bit tricky structure, sometime there is not a main scene loaded, only singletons placed in the tree. Current implementation of variable_tracker can't handle such situations, so I made a deep rework of the module for my needs. Please take a look at the code, may be you will be interested in approving it into your project.

Main changes:

• Proper handle situations when current scene root node not found.
• Auto load singletons detection based on project settings.
• Auto tracking interval now exposed via module settings.
• More detailed tip messages in console.

[Ark2000]

Thank you for your contribution! seems it is a much improved version, I'll check it out later.

[Ark2000]

The pr solved an issue also, https://github.com/Ark2000/PankuConsole/issues/154.

It seems that you are already well acquainted with the code base. I'm excited to see more of your contributions in the future!

[worron]

Fixes done.