feat: Add fail2ban status in health

[BadWolf42]

Description

As requested on Community, this PR adds fail2ban status on health page:

• When fail2ban is started:
  
• When fail2ban is not running:
  
• When fail2ban has failed (not running with errors):
  

Suggested changelog entry

Add Fail2ban Linux service status on health page

Related issues/external references

N/A

Fixes #
N/A

Types of changes

• New feature (non-breaking change which adds functionality)

PR checklist

• I have checked there is no other PR open for the same change.
• I have read the [La ligne directrice pour contribuer à ce projet / Contribution guidelines for this project).
• I grant the project the right to include and distribute the code under the GNU.
• I have added tests to cover my changes.
• I have verified that the code complies with the projects coding standards.
• [Required for new sniffs] I have added MD documentation for the sniff.