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 <[email protected]>
Co-authored-by: Max Peintner <[email protected]>
Co-authored-by: Florian Forster <[email protected]>

login/.github/ISSUE_TEMPLATE/docs.yaml

@@ -0,0 +1,30 @@
+name: 📄 Documentation
+description: Create an issue for missing or wrong documentation.
+labels: ["docs"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for taking the time to fill out this issue.
+  - type: checkboxes
+    id: preflight
+    attributes:
+      label: Preflight Checklist
+      options:
+      - label:
+          I could not find a solution in the existing issues, docs, nor discussions
+        required: true
+      - label:
+          I have joined the [ZITADEL chat](https://zitadel.com/chat)
+  - type: textarea
+    id: docs
+    attributes:
+      label: Describe the docs your are missing or that are wrong
+      placeholder: As a [type of user], I want [some goal] so that [some reason].
+    validations:
+      required: true
+  - type: textarea
+    id: additional
+    attributes:
+      label: Additional Context
+      description: Please add any other infos that could be useful.