150|Refactor: authentication operator changed to author_name property

Description of refactor

• Authentication operator changed to a StringProperty "author_name".

  • utils_ui.draw_author function created to be easily overriden for customization.
  • Whole password logic deleted because up to pipeline.

• Update documentation

• Write tutorial documentation about how to override draw_author to put a sign_in to a production tracker as the main override tutorial: #337

How to test it

Checklist

Please check if your MR fulfills the following requirements:

• Unit tests have been adapted
• Build was run locally and any changes were pushed
• Lint has passed locally without error
• CHANGELOG.md has been updated

FYI: @awesome_dev_too