Append profile to databrickscfg instead of writing the full file (#1060)

## Changes
* Writing the full .databrickscfg leads to unintended consequences such
as deletion of comments and writing invalid profiles.
* We should append to the file instead. 

## Tests
<!-- How is this tested? -->

---------

Co-authored-by: Ilia Babanov <ilia.babanov@databricks.com>

Author: kartikgupta-db

packages/databricks-vscode/src/configuration/LoginWizard.ts

@@ -28,8 +28,9 @@ import {
 } from "@databricks/databricks-sdk";
 import {randomUUID} from "crypto";
 import ini from "ini";
-import {copyFile, writeFile} from "fs/promises";
+import {appendFile, copyFile} from "fs/promises";
 import path from "path";
+import os from "os";
 
 interface AuthTypeQuickPickItem extends QuickPickItem {
     authType?: SdkAuthType;
@@ -370,13 +371,17 @@ export async function saveNewProfile(
     if (!iniData) {
         throw new Error("Can't save empty auth provider to a profile");
     }
-    const {path: configFilePath, iniFile} = await loadConfigFile(
+
+    const {path: configFilePath} = await loadConfigFile(
         workspaceConfigs.databrickscfgLocation
     );
-    iniFile[profileName] = Object.fromEntries(
+
+    const profile: any = {};
+    profile[profileName] = Object.fromEntries(
         Object.entries(iniData).filter((kv) => kv[1] !== undefined)
     );
-
+    const iniStr = ini.stringify(profile);
+    const finalStr = `${os.EOL};This profile is autogenerated by the Databricks Extension for VS Code${os.EOL}${iniStr}`;
     // Create a backup for .databrickscfg
     const backup = path.join(
         path.dirname(configFilePath),
@@ -388,7 +393,7 @@ export async function saveNewProfile(
     );
 
     // Write the new profile to .databrickscfg
-    await writeFile(configFilePath, ini.stringify(iniFile));
+    await appendFile(configFilePath, finalStr);
 
     return new ProfileAuthProvider(authProvider.host, profileName, true);
 }