various fixes

[maxakuru]

• allow empty children in sidenav book sort
• load .plain.html for all fragments, including paths without origins
• set limit query param for fetchJSON calls for book data to 10k

fix #157

Test URLs:

Before: https://main--prisma-cloud-docs-website--hlxsites.hlx.page/prisma/prisma-cloud/en/enterprise-edition/use-cases/visibility-control/use-case1 After: https://maxed-fixes-2--prisma-cloud-docs-website--hlxsites.hlx.page/prisma/prisma-cloud/en/enterprise-edition/use-cases/visibility-control/use-case1

[aem-code-sync[bot]]

Hello, I'm Franklin Bot and I will run some test suites that validate the page speed. In case there are problems, just click the checkbox below to rerun the respective action.

• [ ] Re-run PSI Checks

[aem-code-sync[bot]]

Page	Scores	Audits	Google
/prisma/prisma-cloud/en/enterprise-edition/use-cases/visibility-control/use-case 1

[aem-code-sync[bot]]

Page	Scores	Audits	Google
/prisma/prisma-cloud/en/enterprise-edition/use-cases/visibility-control/use-case 1

[aem-code-sync[bot]]

Page	Scores	Audits	Google
/prisma/prisma-cloud/en/enterprise-edition/use-cases/visibility-control/use-case 1

[aem-code-sync[bot]]

Page	Scores	Audits	Google
/prisma/prisma-cloud/en/enterprise-edition/use-cases/visibility-control/use-case 1