Fastify migration

[giulianok]

Description

This PR is a simpler version of #807. Multiple small PRs are targeting feature/fastify-migration for easy review. Once all PRs are merged into feature/fastify-migration, this PR will look very similar to #807 and all tests will pass

Motivation and Context

How Has This Been Tested?

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]

Size Change: +8.13 kB (+1%)

Total Size: 689 kB

Filename	Size	Change
./build/app/app.js	173 kB	+7.5 kB (+5%)	🔍
./build/app/app~vendors.js	387 kB	+512 B (0%)
./build/app/service-worker-client.js	7.26 kB	-3 B (0%)
./build/app/vendors.js	114 kB	+115 B (0%)

ℹ️ View Unchanged

Filename	Size
./build/app/runtime.js	7.07 kB

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