Enhance Cloudly Configuration and Testing Setup

- Updated README to include architecture overview and details on components.
- Changed import paths in test helpers and test files to use the new Git zone packages.
- Modified S3 bucket name in test setup for consistency.
- Updated CloudlyConfig class to use more descriptive environment variable names for MongoDB and S3 configuration.
- Adjusted ImageManager to retrieve the S3 bucket name from the configuration instead of hardcoding it.

ts/manager.image/classes.imagemanager.ts

@@ -156,7 +156,7 @@ export class ImageManager {
     this.smartbucketInstance = new plugins.smartbucket.SmartBucket(
       this.cloudlyRef.config.data.s3Descriptor,
     );
-    const bucket = await this.smartbucketInstance.getBucketByName('cloudly-test');
+    const bucket = await this.smartbucketInstance.getBucketByName(s3Descriptor.bucketName);
     await bucket.fastPut({ path: 'images/00init', contents: 'init' });
 
     this.imageDir = await bucket.getDirectoryFromPath({