chore(login): migrate nextjs login to monorepo (#10134)

# Which Problems Are Solved

We move the login code to the zitadel repo.

# How the Problems Are Solved

The login repo is added to ./login as a git subtree pulled from the
dockerize-ci branch.
Apart from the login code, this PR contains the changes from #10116

# Additional Context

- Closes https://github.com/zitadel/typescript/issues/474
- Also merges #10116  
- Merging is blocked by failing check because of:
- https://github.com/zitadel/zitadel/pull/10134#issuecomment-3012086106

---------

Co-authored-by: Max Peintner <peintnerm@gmail.com>
Co-authored-by: Max Peintner <max@caos.ch>
Co-authored-by: Florian Forster <florian@zitadel.com>

dockerfiles/typescript-proto-client.Dockerfile.dockerignore

@@ -0,0 +1,11 @@
+*
+!/login/packages/zitadel-proto/
+login/packages/zitadel-proto/google
+login/packages/zitadel-proto/zitadel
+login/packages/zitadel-proto/protoc-gen-openapiv2
+login/packages/zitadel-proto/validate
+
+**/*.md
+**/*.png
+**/node_modules
+**/.turbo