feat: Customizable Sink Files

[jshlbrd]

Description

• Adds support for dynamic file formats, compression, and paths
• Adds a file sink to write data to local disk
• Updates the AWS S3 sink to support new settings (backcompat with current version)
• Adds file and http sink support to the force-sink flag in the dev app

Motivation and Context

Motivation and context is described in https://github.com/brexhq/substation/discussions/91. Here's the impact of this PR:

• Backwards compatible with current version (non-breaking change), but replaces existing configurations
  • Existing file path configs in the AWS S3 sink will be removed in v1.0.0 (whenever that is)
• By default the behavior of the current version is preserved in this change
  • Default file paths are [year]/[month]/[day]/[uuid].gz, file format is JSON, file compression is Gzip
• Every configuration in the custom file path is optional, which will likely lead to unintentional outcomes if users aren't careful
  • Most likely outcome is accidentally overwriting previously written data
  • Not clear how much responsibility the code should take to keep users safe from themselves -- the safest thing to do is always use the default settings (an empty file path config)
• Multiple settings that were hard-coded in the AWS S3 sink were abstracted into a private struct called fw (file wrapper), this provides support for additional custom file format and compression

The file sink was added to test the usefulness of abstracting settings into a reusable struct versus keeping it only for the AWS S3 sink. In my opinion it works fine, and can be reused for other cloud service providers in the future.

How Has This Been Tested?

Locally integration tested all filePath config options using AWS S3 and local files.

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] My code follows the code style of this project.
• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.