pyband: Auth module implementation

[taobun]

Fixed: #2531

Implementation details

• Verify msg from public key.
• Check request status from chian.

Please ensure the following requirements are met before submitting a pull request:

• The pull request is targeted against the correct target branch
• The pull request is linked to an issue with appropriate discussion and an accepted design OR is linked to a spec that describes the work.
• The pull request includes a description of the implementation/work done in detail.
• The pull request includes any and all appropriate unit/integration tests
• You have added a relevant changelog entry to CHANGELOG_UNRELEASED.md
• You have re-reviewed the files affected by the pull request (e.g. using the Files changed tab in the Github PR explorer)

[render]

Your Render PR Server URL is https://d3n-scan-pr-2588.onrender.com.

Follow its progress at https://dashboard.render.com/static/srv-bt5viqn93em3np938qt0.

[sorawit]

typo

[evilpeach]

It should be 2588, not 2577.