[RHINENG-7833] - Send notification newly-stale hosts

[jpramos123]

Overview

This PR is being created to address RHINENG-7833.
It adds the functionality of sending notitications for hosts that went stale in the last X seconds. To define this X seconds, an environment variable called STALE_VALIDATION_WINDOW_SECONDS was created, its default values is set to 1 hour.
It also refacts the host reaper, as this new feature is also a job that runs every certain amount of time. The common code used by both jobs were added to the jobs/common.py file.

PR Checklist

• Keep PR title short, ideally under 72 characters
• Descriptive comments provided in complex code blocks
• Include raw query examples in the PR description, if adding/modifying SQL query
• Tests: validate optimal/expected output
• Tests: validate exceptions and failure scenarios
• Tests: edge cases
• Recovers or fails gracefully during potential resource outages (e.g. DB, Kafka)
• Uses type hinting, if convenient
• Documentation, if this PR changes the way other services interact with host inventory
• Links to related PRs

Secure Coding Practices Documentation Reference

You can find documentation on this checklist here.

Secure Coding Checklist

• Input Validation
• Output Encoding
• Authentication and Password Management
• Session Management
• Access Control
• Cryptographic Practices
• Error Handling and Logging
• Data Protection
• Communication Security
• System Configuration
• Database Security
• File Management
• Memory Management
• General Coding Practices

[jpramos123]

/retest

[FabriciaDinizRH]

I think this needs more tests, but I'll not block it