Implements generator changes needed to execute v9 package restructure outlined by this RFC

Changes

• removes old moveStories function which was used to move stories from src/stories to src/stories/{ComponentName} since that entire migration is now complete.

• Adds moveStoriesToPackageRoot function which will move existing stories from src/stories to /stories. Any new components created with the create-component script will now have their story templates populated in the /stories/{ComponentName} directory.

• Adds moveDocsToSubfolder which moves existing MIGRATION.md and SPEC.md files to the /docs folder.

• Adds migrateE2ESetupToCypress function which moves files within the e2e/ folder to appropriate location
  - moves tsconfig.json to root of package renamed as tsconfig.cy.json. This is then added to base tsconfig.json's path references.
  - moves any file with .e2e. suffix to src/components/{ComponentName} with filename updated to use .cy. suffix.
  - moves any selector.ts helper files to src/testing and updates any import paths of files that require it.

• Adds migrateCommonFolderToTesting function which moves any file present in the src/common folder to src/testing and updates the import paths of files that require moved files.

• Updates npm.ignore file to ignore /docs and /stories subfolders and any files with .cy. in its path.

• Renames instances where function names are referred to as e2e in favor of cypress

Example Usage:

Draft PR which uses generator: #25015

Related Issues:

Part of #24129