Slow Response Monitoring Visual Improvements

[stephenpapierski]

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Description

Adds Visual Elements to #4005
Fixes #4035

This pull request generally adds visual flair to the work done in #4005 . Since all changes are visual, change details are listed under screenshots below.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• User interface (UI)
• New feature (non-breaking change which adds functionality)

Checklist

• My code follows the style guidelines of this project
• I ran ESLint and other linters for modified files
• I have performed a self-review of my own code and tested it
• I have commented my code, particularly in hard-to-understand areas (including JSDoc for methods)
• My changes generates no new warnings
• My code needed automated testing. I have added them (this is optional task)

Screenshots

• Add threshold line to ping chart
  • 
• Add Slow badge to monitor dashboard when service is responding slow (no badge when Nominal)
  • 
• Add Slow/Nominal entries to events log
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• Add Slow/Nominal toast messages
  • 
  • 
• Add number of Slow services to Dashboard Quick Stats
  • 

[stephenpapierski]

Merged into #4005