Update file header, add const for defaults, and update log messages

[fabaff]

Description:

Update file header, add const for defaults, and update log messages

Example entry for configuration.yaml (if applicable):

binary_sensor:
  - platform: flic

Checklist:

If the code communicates with devices, web services, or third-party tools:

• Local tests with tox run successfully. Your PR cannot be merged unless tests pass

[mention-bot]

@fabaff, thanks for your PR! By analyzing the history of the files in this pull request, we identified @soldag and @armills to be potential reviewers.