feat: Workspace name field optional

[joyanedel]

Problem

Pixi requires users to write workspace.name field in pixi.toml
Despite the fact, not doing this could be consider a bad practice, some users seems to like a little bit of freedom on this aspect as user in issue #3431 is proposing.

Solution

Add root directory name as a fallback in case of field name not being defined in pixi.toml file.
If for some reason the root_directory is None, it returns the MissingField error.

[trim21]

I'm not sure what's the difference between project and workspace, but looks like it also affect project.name?

[trim21]

OH, sorry, wrong comment location, I mean line 36, if project.name is missing it should still raise a error?

[joyanedel]

You're right. The project.name field shouldn't be affected by this new feature. I made a mistake when updating the documentation. Thanks for noting it

[joyanedel]

Seems to be a documentation version drift between what I forked vs official documentation. In the official documentation, the pixi manifest section indicates that the project table starts with a [project] statement but in main branch, the same section states the project table starts with [workspace] statement.

Of course, my intention is to indicate that, in the workspace section, the name is not required anymore

@baszalmstra I tagged you because I understand that you are very involved in pixi project. How should we update the documentation to indicate this new change?

[baszalmstra]

Thank you very much for this PR. I accidentally also implemented a solution in #3526 . I went with a slightly different approach and added a few tests.