Updates DbtCloudCredentials to implement CredentialsBlock interface

[desertaxle]

Updates DbtCloudCredentials to implement CredentialsBlock interface. In order to achieve this, I added an additional DbtCloudMetadataClient for querying the dbt Cloud metadata API. The DbtCloudCredentials block is now able to return two different clients with its .get_client method.

Example

Using the metadata client:

from prefect_dbt import DbtCloudCredentials

credentials_block = DbtCloudCredentials.load("test-account")
metadata_client = credentials_block.get_client("metadata")
query = """
{
  metrics(jobId: 123) {
    uniqueId
    name
    packageName
    tags
    label
    runId
    description
    type
    sql
    timestamp
    timeGrains
    dimensions
    meta
    resourceType
    filters {
       field
       operator
       value
     }
    model {
      name
    }
  }
}
"""
metadata_client.query(query)
# Result:
# {
#   "data": {
#     "metrics": [
#       {
#         "uniqueId": "metric.tpch.total_revenue",
#         "name": "total_revenue",
#         "packageName": "tpch",
#         "tags": [],
#         "label": "Total Revenue ($)",
#         "runId": 108952046,
#         "description": "",
#         "type": "sum",
#         "sql": "net_item_sales_amount",
#         "timestamp": "order_date",
#         "timeGrains": ["day", "week", "month"],
#         "dimensions": ["status_code", "priority_code"],
#         "meta": {},
#         "resourceType": "metric",
#         "filters": [],
#         "model": { "name": "fct_orders" }
#       }
#     ]
#   }
# }

Screenshots

Checklist

• References any related issue by including "Closes #" or "Closes ".
  • If no issue exists and your change is not a small fix, please create an issue first.
• Includes tests or only affects documentation.
• Passes pre-commit checks.
  • Run pre-commit install && pre-commit run --all locally for formatting and linting.
• Includes screenshots of documentation updates.
  • Run mkdocs serve view documentation locally.
• Summarizes PR's changes in CHANGELOG.md

[ahuang11]

Looks good to me!

[ahuang11]

Is the \ needed here?

[desertaxle]

Yeah, need to escape the quotes so that the docstring continues.