Use 'artifacts' instead of .artifacts for default artifacts path

[dsplaisted]

Based on feedback from the .NET 8 Preview 3 support for artifacts output, this PR removes the . from the default artifacts output path.

It also blocks setting the artifacts path in the project file instead of in Directory.Build.props. Reasons for this include:

• With the . removed, adding a new folder inside the project path would cause problems, since the new folder wouldn't be excluded from the default item includes
• It would be unexpected that simply adding an empty Directory.Build.props file to your repo would move the artifacts path from the project folder up the tree to where the Directory.Build.props file was
• Making it an error now might make it easier to change the heuristic in the future to look for .sln files, which might enable us to turn on the new output path format by default for some future TargetFramework.

Some things I still want to add to this PR:

• Add an error if you set UseArtifactsOutput to true on the command line but don't have a Directory.Build.props file.
• Add properties that allow you to opt in to putting the artifacts output in the project folder if you want, and to prevent the project name from being added to the path afterwards.
• Verify that artifacts path is removed from globs

[dotnet-issue-labeler]

I couldn't figure out the best area label to add to this PR. If you have write-permissions please help me learn by adding exactly one area label.

[baronfel]

Wording of the message and the . removal looks great to me 👍

[timheuer]

I feel like we should also PR adding artifacts then to default .NET .gitignore files across the ecosystem then (similar to how dist is on default for JS apps

[baronfel]

@timheuer it's already in the gitignore for the .NET CLI templates and the community-maintained ones at github/gitignore, so we should be covered.

[joeloff]

Do we need to manually lock the ArtifactsPath and UseArtifactsOutput strings inside a <note /> section for the translators so they cannot translate the property names by accident?

[dsplaisted]

Might be a good idea, can you point me to an example of what that looks like?

[nagilson]

You can add something like:
<note>{Locked="dotnet workload search"}</note>
if dotnet workload search is what you want to lock.

This PR has a lot of examples: https://github.com/dotnet/sdk/pull/28553/files

[joeloff]

In the ENU resx file you should be able to add something like

<comment>{Locked="ArtifactsPath"} {Locked="UseArtifactsOutput"}</comment>

The comments will automatically be added in the XLF as notes for the translators IIRC. I can't remember if you need a single comment or multiple comments with separate locks. I think it's the former

[joeloff]

Should this be inside the PropertyGroup on line 67 (it has the same condition)?

[dsplaisted]

Good idea, but I will try to do that later since I'd like to get this in before we branch for Preview 4.

[nagilson]

I think this is a great change. With that said, this is technically a breaking change even though it only breaks one preview to preview version. Im not sure what our modus operandi here is but IMO we should create a breaking change doc, especially since this is removing a feature, we should do all we can to give clarity as to why we took something away and how to fix it.