Add support for environment variables in faststream run command

[ulbwa]

Description

• FASTSTREAM_WORKERS as an alternative to the --workers argument
• FASTSTREAM_APP_DIR as an alternative to --app-dir
• FASTSTREAM_LOG_LEVEL as an alternative to --log-level

Fixes # (issue number)

Type of change

Please delete options that are not relevant.

• [x] New feature (a non-breaking change that adds functionality)
• [x] This change requires a documentation update

Checklist

• [x] My code adheres to the style guidelines of this project (scripts/lint.sh shows no errors)
• [x] I have conducted a self-review of my own code
• [ ] I have made the necessary changes to the documentation
• [x] My changes do not generate any new warnings
• [ ] I have added tests to validate the effectiveness of my fix or the functionality of my new feature
• [x] Both new and existing unit tests pass successfully on my local environment by running scripts/test-cov.sh
• [x] I have ensured that static analysis tests are passing by running scripts/static-analysis.sh
• [ ] I have included code examples to illustrate the modifications