Update custom drawing in 2d tutorial to Godot4

[jynus]

This tutorial had 2 main issues: the code wasn't adapted to Godot
4 syntax and API and the suggested tutorial contained information
to workaround the (at the time) non existence of the draw_arc()
function.

A general update has been made, keeping the general structure but
changing the example for something more useful and fun
(replicating the godot logo with draw primitives) and an
additional example with a dynamically built drawing (dynamic line).

Too many informalities have been removed on the initial paragraph.
Fixed references to Texture instead of Texture2D.
Fixed old style of exporting properties to the editor.
Fixed inconsistencies calling Node2D, myNode2D and customNode2D.
Moved examples to the end of the page, leaving general information
at the top, and completing that info with images and references.

Fixes #4184
Fixes #7521

[jynus]

I have simplified the last part, I think it makes no sense to have complex code on a tutorial- I will send an amend soon after I test following it works.

[jynus]

I think this version makes more sense- tutorials should be simple and show clear examples on how to use a library, even at the cost of showing more useful, and more realistic code.

[jynus]

Any update on this? I know it is a large change, but I think it is better than the old tutorial; and we can always improve on top of it- or if you can provide me some feedback I would appreciate it.

[AThousandShips]

Style, syntax, and formatting details

[AThousandShips]

Also please use rebasing to update your branch, see here

[jynus]

I think I applied all suggestions, but please give me some time to go over the tutorial again, to make sure I didn't miss anything and neither gdscript nor csharp code got broken while amending it, and can be followed well by a beginner.

[AThousandShips]

You have missed a few in the middle

[jynus]

I have fixed a few additional typos and minor expressions while redoing the tutorial for both gdscript and C#, also ensuring there was a lower possibility of confusion. While I cannot be sure 100% this is error-free, I feel now more confident after my last amend and this is ready for review.

[jynus]

Will now squash, rebase and do the pending changes (_t) before testing.

[jynus]

FYI for the mean time, I just merged #7994

While rebasing I noticed the merged quick fix has a bug. Not a big deal, as the rebase I did will fix it anyway. This is why it is important to test the code- which is my next task here.

[jynus]

Build failed after rebase due to cd92be0 , updating that too.

[jynus]

I am rechecking now all code snippets, please give me some time. I think it is important to go over it at least once.

[jynus]

I am happy with the current version, to my knowledge I have applied all suggestions and I have also tested that the functionality keeps working.

[raulsntos]

The C# code looks good and works as expected, thanks for contributing!

[skyace65]

Thanks! And thanks for dealing with the long review process, this is definitely a major improvement for the docs.

[jynus]

Thanks, I learned a lot, so hopefully future patches I can do them faster. Please if you have some linters you can recommend me for style checking, I would welcome them, specially on the C# side.

I would also like to thank you all for the help and the patience with me. :-)

[mhilbrunner]

Cherry-picked to 4.2.