Split CLI modules into separate packages

Extract each CLI module from packages/cli/src/modules/ into its own
package under packages/cli-module-*. This enables independent versioning
and clearer dependency boundaries for each CLI capability.

Module mapping:
- auth → @backstage/cli-module-auth
- build → @backstage/cli-module-build
- config → @backstage/cli-module-config
- create-github-app → @backstage/cli-module-create-github-app
- info → @backstage/cli-module-info
- lint → @backstage/cli-module-lint
- maintenance → @backstage/cli-module-maintenance
- migrate → @backstage/cli-module-migrate
- new → @backstage/cli-module-new
- test → @backstage/cli-module-test-jest
- translations → @backstage/cli-module-translations

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
Made-with: Cursor

packages/cli-module-auth/.eslintrc.js

@@ -0,0 +1 @@
+module.exports = require('@backstage/cli/config/eslint-factory')(__dirname);