[Hubs] Ingest GCP billing data

[flanakin]

📝 Scenario

As a hub admin, I need to connect my hub to Google Cloud in order to monitor GCP and Microsoft Cloud costs in a single pane of glass

💎 Solution

Create a pipeline to ingest FOCUS cost data from Google Cloud Storage into the ingestion container.

📋 Tasks

### Required tasks
- [x] Create base pipeline
- [x] Upload files 
- [ ] Add the linked service and dataset -- #1542 
- [ ] Add the trigger
- [ ] Add onboarding doc
- [ ] Update marketing page
- [ ] Update hubs overview doc
- [ ] Validation -- We will need help from others. Please leave a comment if you can help!

### Stretch goals
- [ ] Add file uploading to the hub-storage module -- #1543 
- [ ] Change file uploading to use the hub-storage module
- [ ] How can columns be customized (e.g., add custom x_ResourceGroupName column)

🙋‍♀️ Ask for the community

We could use your help:

1. Please vote this issue up (👍) to prioritize it.
2. Leave comments to help us solidify the vision.