Migrate IBM Cloud Databases fetchers with multiple resource_group_ids enhancement

## Overview

We need to migrate the IBM Cloud Databases list and backups list fetchers.

## Requirements

- Should not depend on ibmcloud_tools
- Fetcher should handle multiple resource_group_id's per account while being backward compatible

## Approach

TBD

## Security and Privacy

N/A

## Test Plan

Local environment to be set up and evidence fetched

Locate the IBM Cloud Databases list and backups list fetchers and find their dependency on ibmcloud_tools. Set up the local environment described in the test plan, then verify multiple resource_group_ids per account and backward compatibility using fetched evidence.

Written by the indexing model from the issue text.