feat(lsp): ability to configure document pre-load limit (#19097)

Adds a `deno.preloadLimit` option (ex. `"deno.preloadLimit": 2000`)
which specifies how many file entries to traverse on the file system
when the lsp loads or its configuration changes.

Closes #18955

cli/tests/integration/lsp_tests.rs

@@ -7418,6 +7418,49 @@ fn lsp_closed_file_find_references() {
   client.shutdown();
 }
 
+#[test]
+fn lsp_closed_file_find_references_low_document_pre_load() {
+  let context = TestContextBuilder::new().use_temp_cwd().build();
+  let temp_dir = context.temp_dir();
+  temp_dir.create_dir_all("sub_dir");
+  temp_dir.write("./other_file.ts", "export const b = 5;");
+  temp_dir.write("./sub_dir/mod.ts", "export const a = 5;");
+  temp_dir.write(
+    "./sub_dir/mod.test.ts",
+    "import { a } from './mod.ts'; console.log(a);",
+  );
+  let temp_dir_url = temp_dir.uri();
+  let mut client = context.new_lsp_command().build();
+  client.initialize(|builder| {
+    builder.set_preload_limit(1);
+  });
+  client.did_open(json!({
+    "textDocument": {
+      "uri": temp_dir_url.join("sub_dir/mod.ts").unwrap(),
+      "languageId": "typescript",
+      "version": 1,
+      "text": r#"export const a = 5;"#
+    }
+  }));
+  let res = client.write_request(
+    "textDocument/references",
+    json!({
+      "textDocument": {
+        "uri": temp_dir_url.join("sub_dir/mod.ts").unwrap(),
+      },
+      "position": { "line": 0, "character": 13 },
+      "context": {
+        "includeDeclaration": false
+      }
+    }),
+  );
+
+  // won't have results because the document won't be pre-loaded
+  assert_eq!(res, json!([]));
+
+  client.shutdown();
+}
+
 #[test]
 fn lsp_data_urls_with_jsx_compiler_option() {
   let context = TestContextBuilder::new().use_temp_cwd().build();