C#: Make editor create NuGet fallback folder for Godot packages

[neikeq]

Main benefits:

• Projects can be built offline. Previously you needed internet access the first time building to download the Godot packages (Godot.NET.Sdk).
• Changes to packages like Godot.NET.Sdk can be easily tested before publishing. This was already possible but required too many manual steps.
• First time builds are a bit faster, as the Sdk package doesn't need to be downloaded. In practice, the package is very small so it makes little difference.

Bumped Godot.NET.Sdk to 4.0.0-dev3 in order to enable the recent changes regarding .mono/ -> .godot/mono/.

[neikeq]

This will be backported to the 3.2 branch later, but we probably want to give it a bit more time to be tested.

[akien-mga]

#43028 is merged, git rebase upstream master should remove the now merged commit from this PR.

[neikeq]

#43028 is merged, git rebase upstream master should remove the now merged commit from this PR.

I was crossing my fingers in hope GitHub would magically take care of that 😄

[neikeq]

Looks like I have to update my pre-commit hooks... :(

[aaronfranke]

.godot/.mono/

Note: It's actually .godot/mono, we don't need to hide the folder twice.

[neikeq]

@akien-mga Are the CI static checks different from the pre-commit hooks in any way? Mine don't trigger any error. Perhaps it's my formatter version:

~ $ black --version
black, version 19.3b0

[akien-mga]

@neikeq That one is ran manually by the CI: misc/scripts/file_format.sh
It's not part of pre-commit hooks because it's slow as it parses all repo files instead of the ones changed by the commit, like the pre-commit hooks do.

[aaronfranke]

Here the failing check is "Python style checks via black (black_format.sh)"

Black is pinned to 20.8b1: https://github.com/godotengine/godot/blob/master/.github/workflows/static_checks.yml#L22

[akien-mga]

Ah yes, black changes its mind on how to reflow long strings all the time, so it's important to use the current stable version which we're tracking (in the past we used master as there was no recent release and there was an important bugfix we needed, but now it's in 20.8b1).

[aaronfranke]

I did a little testing. In the current master, building fails due to the mismatch of .mono/ and .godot/mono/. With this PR, pressing the build button causes the editor to crash, but the good news is that it didn't create the .mono/ folder :P

Anyway, here's a minimal test project, including .godot/mono/ and the logs I get when building: Test.zip For reference I'm on Ubuntu 20.04 with Mono 6.12.0.90 and .NET Core 3.1.403. I also had to copy over the csproj and sln files from a Godot 3 project and modify them, because I'm not able to open the Create Script menu without freezing my entire computer. Oh and also here's the terminal output: terminal-output.txt

[neikeq]

@aaronfranke Thanks. Custom event signals weren't doing hot-reload properly. #43088 fixes it.

[aaronfranke]

Tested in combination with #43088 and it works. I don't understand all this code but it looks fine.

Note: I didn't test offline builds, but at least the online builds work now unlike the current master.

[akien-mga]

Thanks!