Move assets to their own crate, load keymaps in vim tests

Also, move assets folder to the top-level.

Co-authored-by: Keith Simmons <keith@zed.dev>

crates/assets/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "assets"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+path = "src/assets.rs"
+doctest = false
+
+[dependencies]
+gpui = { path = "../gpui" }
+anyhow = "1.0.38"
+rust-embed = { version = "6.3", features = ["include-exclude"] }
+

crates/assets/src/assets.rs

@@ -0,0 +1,20 @@
+use anyhow::{anyhow, Result};
+use gpui::AssetSource;
+use rust_embed::RustEmbed;
+
+#[derive(RustEmbed)]
+#[folder = "../../assets"]
+#[exclude = "*.DS_Store"]
+pub struct Assets;
+
+impl AssetSource for Assets {
+    fn load(&self, path: &str) -> Result<std::borrow::Cow<[u8]>> {
+        Self::get(path)
+            .map(|f| f.data)
+            .ok_or_else(|| anyhow!("could not find asset at path \"{}\"", path))
+    }
+
+    fn list(&self, path: &str) -> Vec<std::borrow::Cow<'static, str>> {
+        Self::iter().filter(|p| p.starts_with(path)).collect()
+    }
+}