introduces mapSchemaConfig utility function

[yaacovCR]

motivation:

1. rebuilds lexicographicallySortSchema on this generic utility, better demonstrating only the sorting
2. rebuilds extendSchemaImpl on this utility
3. can be used as base to more easily enhance extendSchema/buildASTSchema/buildSchema to take resolvers, etc
4. can be used to expose a generic safe mapSchema utility

TO DO: improve test coverage

[netlify]

✅ Deploy Preview for compassionate-pike-271cb3 ready!

Name	Link
🔨 Latest commit	e495a3f
🔍 Latest deploy log	https://app.netlify.com/sites/compassionate-pike-271cb3/deploys/67450d5b1b5cbe0008ab9706
😎 Deploy Preview	https://deploy-preview-4297--compassionate-pike-271cb3.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[github-actions]

Hi @yaacovCR, I'm @github-actions bot happy to help you with this PR 👋

Supported commands

Please post this commands in separate comments and only one per comment:

• @github-actions run-benchmark - Run benchmark comparing base and merge commits for this PR
• @github-actions publish-pr-on-npm - Build package from this PR and publish it on NPM

[yaacovCR]

note: diff is easier to scan when hiding whitespace

[yaacovCR]

This re-implementation brings a 24% performance boost to buildSchema() and a small drop in memory use.

I'm not sure yet what exactly brings the performance boost, I was just hoping for parity.

[yaacovCR]

Just poking around a bit with deopt-explorer, which, as usual, is beyond me, but the summary for main is:

and the summary for map is:

For clarity, within the map version, we rename getWrappedType() to typeFromAST() and getNamedType() to namedTypeFromAST() because it allows us to use getNamedType() in the SchemaContext closure without a clash -- and these functions essentially are a pre-GraphQLSchema-creation version of our typeFromAST() utility with the exact same algorithm.

For clarity, I also renamed buildType() to buildNamedType().

So the thing that leaps out at me is that the number of deoptimizations in buildType()/buildNamedType() and extendSchemaImpl() drop, the former significantly. I am not 100% on why. I can only guess that splitting the functions into smaller bits helped.