ci: Enable schema build for monorepo

[maxreichmann]

JIRA: CPOUI5FOUNDATION-1162

• Schema build script moved to internal/documentation/scripts/
  • allows a parameter to set if schema should be based on local state or latest published npm state
• npm scripts for this regard moved to internal/documentation/
• Deployment CI jobs adjusted (but still disabled till final v5 release)
• Changes in local workspace will be reflected in local build of schema
  • CI will generate schemas based on latest published npm version

[coveralls]

coverage: 94.657% (-0.01%) from 94.67%
when pulling 5354155 on ci/setup-schema-build
into 8938c72 on main.