prefect-dbt: from_file method for TargetConfigs

[robfreedy]

First check

• [X] I added a descriptive title to this issue.
• [X] I used the GitHub search to find a similar request and didn't find it.
• [X] I searched the Prefect documentation for this feature.

Prefect Version

2.x

Describe the current behavior

Currently, you have to define a TargetConfigs block with Database/Data Warehouse configurations manually in python code or in the Prefect UI, which can then get passed to the DbtCliProfile to save the credentials. This usually means a lot of copying and pasting from the dbt profiles.yml or elsewhere.

Describe the proposed behavior

Add a from_file method to the TargetConfigs block to automatically populate the credentials and config into a new instance of a TargetConfigs block given an existing dbt profiles.yml file.

Example Use

target_configs = TargetConfigs.from_file(file_path="/path/to/profileyaml/.dbt/profile.yml")
dbt_cli_profile = DbtCliProfile(
            name="jaffle_shop",
            target="dev",
            target_configs=target_configs,
        )

Additional context

No response