Fix missed renames in #22632 (#23688)

Fix a bug where a GPUI macro still used `ModelContext`
Rename `AsyncAppContext` -> `AsyncApp`
Rename update_model, read_model, insert_model, and reserve_model to
update_entity, read_entity, insert_entity, and reserve_entity

Release Notes:

- N/A

crates/prettier/src/prettier.rs

@@ -1,7 +1,7 @@
 use anyhow::{anyhow, Context as _};
 use collections::{HashMap, HashSet};
 use fs::Fs;
-use gpui::{AsyncAppContext, Entity};
+use gpui::{AsyncApp, Entity};
 use language::{language_settings::language_settings, Buffer, Diff};
 use lsp::{LanguageServer, LanguageServerId};
 use node_runtime::NodeRuntime;
@@ -235,7 +235,7 @@ impl Prettier {
         _: LanguageServerId,
         prettier_dir: PathBuf,
         _: NodeRuntime,
-        _: AsyncAppContext,
+        _: AsyncApp,
     ) -> anyhow::Result<Self> {
         Ok(Self::Test(TestPrettier {
             default: prettier_dir == default_prettier_dir().as_path(),
@@ -248,7 +248,7 @@ impl Prettier {
         server_id: LanguageServerId,
         prettier_dir: PathBuf,
         node: NodeRuntime,
-        cx: AsyncAppContext,
+        cx: AsyncApp,
     ) -> anyhow::Result<Self> {
         use lsp::{LanguageServerBinary, LanguageServerName};
 
@@ -305,7 +305,7 @@ impl Prettier {
         buffer: &Entity<Buffer>,
         buffer_path: Option<PathBuf>,
         ignore_dir: Option<PathBuf>,
-        cx: &mut AsyncAppContext,
+        cx: &mut AsyncApp,
     ) -> anyhow::Result<Diff> {
         match self {
             Self::Real(local) => {