Add support for fs.stat and fs.appendFile about lune

[RuizuKun-Dev]

would be nice if it returns "a symbolic link" correctly

[CompeyDev]

would be nice if it returns "a symbolic link" correctly

This is already something which fs.metadata should support, although I think this is a bug due to which it doesn't behave as expected.

Not sure what fs.stat would do different from fs.isFile/fs.isDir and fs.metadata combined, other than being more convenient.

[RuizuKun-Dev]

fs.metadata doesn't return "is a symbolic link" last time i checked, and there hasn't been any notes on releases that indicates a fix

i figured it might be easier to implement this and make it work correctly rather than fix fs.metadata, 🤷🏻‍♂️

[CompeyDev]

The metadata method is supposed to support the following types:

lune/crates/lune-std-fs/src/metadata.rs

Lines 13 to 19 in b585234

	#[derive(Debug, Clone, Copy, PartialEq, Eq)]
	pub enum FsMetadataKind {
	None,
	File,
	Dir,
	Symlink,
	}

As stated before, there's a bug which doesn't correctly identify symlinks. It makes more sense to fix incorrect behavior instead introducing a new feature to overshadow it.