First check

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

Describe the current behavior

Currently, Prefect's UI and CLI do not offer functionality to create Blocks from YAML or configuration files. This limitation makes it challenging to manage information efficiently.

Describe the proposed behavior

Add functionality to create Blocks from configuration files in Prefect's UI or CLI.

Example Use

prefect blocks load config.yaml 

The contents of config.yaml

string/test-string:
  value: test-value
sqlalchemy-connector/db-uri:
  connection_info:
    driver: postgresql asyncpg
    database: test-db
    username: user
    password: password
    host: localhost
    port: "5432"

Additional context

Consider adding an overwrite option when creating or updating Blocks. This feature would be useful during execution.