Docs: Update version references to v0.27.0 in READMEs and docs (#18500)

### What problem does this PR solve?

- Update version tags in README files (including translations) from
v0.26.4 to v0.27.0
- Modify Docker image references and documentation to reflect new
version
- Update version badges and image descriptions
- Maintain consistency across all language variants of README files

### Type of change

- [x] Documentation Update

uv.lock

@@ -8112,7 +8112,7 @@ wheels = [
 
 [[package]]
 name = "ragflow"
-version = "0.26.4"
+version = "0.27.0"
 source = { virtual = "." }
 dependencies = [
     { name = "agentrun-sdk" },