Use app router template

[gautamsi]

ref #9183

Blocked by

• Return ResolvedKeystoneConfig instead of KeystoneConfig #9189

This PR updates the template to generate the App router, default to typescript version which can be turned off by setting config.ui.tsx = false

What is completed/Verified:

• generate app routes in app/(admin) folder (creates admin route specific layout page. if src page exist, it generates it in `src/app/(admin)
• Stop generating next.config.js file, this should be generated from create-keystone-app going forward (TODO)
• set default ui.basePath to /admin can set ui.basePath to /admin or any other sub path
• No longer copies admin files or generates pages export copy as they are no longer needed
• Does not clear the admin folder files if exist, only overwrites the special config files which contains up to date admin meta and view cache, this should be removed before GA
• Verified custom pages
• Verified custom fields and field views
• can use relative path or even "paths" from typescript (@fields/text/myView)
• Added --reset-admin flag to dev command to force clean (admin) folder, useful in regenerate the admin template if updated in future. should never be needed except braking upgrade
• fix build and start script
• @keystone-6/auth templates
• page middleware

Pending:

• Documentation
• fixing final set of failing tests

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@dcousens can you create a v-next branch which should be actual target for these PRs instead of main

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[gautamsi]

@dcousens I will need some help in fixing tests,
* smoke tests never finishes
* wired error in package unit tests, it has mismatch on keystone error message in build but unable to trace.
* random test failure with checkForTooManyEngines prisma error

I have disabled some ui tests, they need fixes but we can do that before merging to main

@dcousens I have fixed most test cases, these tests definitely helped me fix a lot of issues.

I see that document-field test can not be fixed due to static generation, I may have missed something.

Test live-reloading.test is not behaving properly, same thing, trying to fix some page router vs app router thing. I am having trouble debugging locally on windows for some reason.

[dcousens]

@gautamsi I'm super busy and can't engage on this this week, but, I'll wrap back around as soon as I can and help move this forward 💛

[gautamsi]

@dcousens I have not generated default files for all the example/test projects, have modified the code as such it will generate all the required nextjs files for dev and build. User would need to commit them in git.

The file generation is one time except the .admin/index file which generates the admin meta has and static keystone props for admin.

[gautamsi]

This part of live reload is not needed, we do not even need to figure out file linking from main dir to isolated dir anymore