Add an extensions installation view (#7689)

This PR adds a view for installing extensions within Zed.

My subtasks:

- [X] Page Extensions and assign in App Menu
- [X] List extensions 
- [X] Button to Install/Uninstall
- [x] Search Input to search in extensions registry API
- [x] Get Extensions from API
- [x] Action install to download extension and copy in /extensions
folder
- [x] Action uninstall to remove from /extensions folder
- [x] Filtering
- [x] Better UI Design

Open to collab!

Release Notes:

- Added an extension installation view. Open it using the `zed:
extensions` action in the command palette
([#7096](https://github.com/zed-industries/zed/issues/7096)).

---------

Co-authored-by: Max Brunsfeld <maxbrunsfeld@gmail.com>
Co-authored-by: Marshall <marshall@zed.dev>
Co-authored-by: Carlos <foxkdev@gmail.com>
Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>
Co-authored-by: Max <max@zed.dev>

crates/extension/src/extension_store_test.rs

@@ -7,16 +7,23 @@ use language::{LanguageMatcher, LanguageRegistry};
 use serde_json::json;
 use std::{path::PathBuf, sync::Arc};
 use theme::ThemeRegistry;
+use util::http::FakeHttpClient;
 
 #[gpui::test]
 async fn test_extension_store(cx: &mut TestAppContext) {
     let fs = FakeFs::new(cx.executor());
+    let http_client = FakeHttpClient::with_200_response();
 
     fs.insert_tree(
         "/the-extension-dir",
         json!({
             "installed": {
                 "zed-monokai": {
+                    "extension.json": r#"{
+                        "id": "zed-monokai",
+                        "name": "Zed Monokai",
+                        "version": "2.0.0"
+                    }"#,
                     "themes": {
                         "monokai.json": r#"{
                             "name": "Monokai",
@@ -53,6 +60,11 @@ async fn test_extension_store(cx: &mut TestAppContext) {
                     }
                 },
                 "zed-ruby": {
+                    "extension.json": r#"{
+                        "id": "zed-ruby",
+                        "name": "Zed Ruby",
+                        "version": "1.0.0"
+                    }"#,
                     "grammars": {
                         "ruby.wasm": "",
                         "embedded_template.wasm": "",
@@ -82,6 +94,12 @@ async fn test_extension_store(cx: &mut TestAppContext) {
     .await;
 
     let mut expected_manifest = Manifest {
+        extensions: [
+            ("zed-ruby".into(), "1.0.0".into()),
+            ("zed-monokai".into(), "2.0.0".into()),
+        ]
+        .into_iter()
+        .collect(),
         grammars: [
             (
                 "embedded_template".into(),
@@ -169,6 +187,7 @@ async fn test_extension_store(cx: &mut TestAppContext) {
         ExtensionStore::new(
             PathBuf::from("/the-extension-dir"),
             fs.clone(),
+            http_client.clone(),
             language_registry.clone(),
             theme_registry.clone(),
             cx,
@@ -201,6 +220,11 @@ async fn test_extension_store(cx: &mut TestAppContext) {
     fs.insert_tree(
         "/the-extension-dir/installed/zed-gruvbox",
         json!({
+            "extension.json": r#"{
+                "id": "zed-gruvbox",
+                "name": "Zed Gruvbox",
+                "version": "1.0.0"
+            }"#,
             "themes": {
                 "gruvbox.json": r#"{
                     "name": "Gruvbox",
@@ -260,6 +284,7 @@ async fn test_extension_store(cx: &mut TestAppContext) {
         ExtensionStore::new(
             PathBuf::from("/the-extension-dir"),
             fs.clone(),
+            http_client.clone(),
             language_registry.clone(),
             theme_registry.clone(),
             cx,