feat(dns): add option to enable app-level DNS caching

[10xLaCroixDrinker]

Description

Add option in appConfig to enable app-level DNS caching via cacheable-lookup

Motivation and Context

Perf enhancement

How Has This Been Tested?

Implemented in a module.

Unit tests

Types of Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation (adding or updating documentation)
• Dependency update
• Security update

Checklist:

• My change requires a change to the documentation and I have updated the documentation accordingly.
• These changes should be applied to a maintenance branch.
• This change requires cross browser checks.
• Performance tests should be ran against the server prior to merging.
• This change impacts caching for client browsers.
• This change impacts HTTP headers.
• This change adds additional environment variable requirements for One App users.
• I have added the Apache 2.0 license header to any new files created.

What is the Impact to Developers Using One App?

[github-actions]

📊 Bundle Size Report

file name	size on disk	gzip
app.js	314.7KB	93.4KB
runtime.js	15.6KB	5.5KB
vendors.js	148.2KB	47.6KB
app~vendors.js	431.2KB	112.6KB
service-worker-client.js	17.1KB	5.3KB
legacy/app.js	335.6KB	98.3KB
legacy/runtime.js	15.6KB	5.5KB
legacy/vendors.js	211KB	59.7KB
legacy/app~vendors.js	453KB	118.3KB
legacy/service-worker-client.js	17.6KB	5.5KB

Generated by 🚫 dangerJS against 33e9e30

[JAdshead]

just a little more info in docs

[JAdshead]

for other reviewers - https://github.com/szmarczak/cacheable-lookup/blob/master/source/index.js#L88