Add ApolloServer direct testing support via strongly typed executeOperation

[cuzzlor]

What ?

We have been using the ApolloServer v4 instance executeOperation function to support testing GraphQL servers without using the network. You might call this a 'subcutaneous' testing approach for a GraphQL implementation.

We don't have any common helpers to assist yet in our libs, so this attempts to take the core of what helps set up testing infrastructure using this approach.

How

Before you review, please note the Also section below (lots of accompanying changes). The following changes are isolated to the ./src/testing folder

• Add strongly typed executeOperation factory function to facilitate running operations using strong typing via TypedDocumentNode
• Add utils to assist creating GraphQL contexts for operations
• Add a complete working vitest example
• Add doc

Also

The following things outside of the above changes to the to the ./src/testing folder.

commit: run ts-toolkit init, prepare for vitest

• Run ts-toolkit across this lib to make it more consistent with others: APOLOGIES FOR ALL THE CHANGED FILES !!
• Upgrade all packages
• Fix a type def with latest new ApolloServer on the logging plugins
• Update GH workflows to use NodeJS v20 and to output test results