Move config files to CLI modules with lazy proxies

Move jest config files to cli-module-test-jest/config and node
transform + webpack-public-path to cli-module-build/config. Replace
originals in @backstage/cli/config with lazy proxies that forward
to the appropriate module or throw if it is not installed.

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

packages/cli/package.json

@@ -49,6 +49,8 @@
   "dependencies": {
     "@backstage/cli-common": "workspace:^",
     "@backstage/cli-defaults": "workspace:^",
+    "@backstage/cli-module-build": "workspace:^",
+    "@backstage/cli-module-test-jest": "workspace:^",
     "@backstage/cli-node": "workspace:^",
     "@backstage/errors": "workspace:^",
     "@backstage/eslint-plugin": "workspace:^",