### What problem does this PR solve?

Unified API response json schema

### Type of change

- [x] Refactoring

### What problem does this PR solve?

Not sure why MySQL is inserting empty string in this case, but when I
use postgres I got `null value in column "invited_by" of relation
"user_tenant" violates not-null constraint`

### Type of change

- [X] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?
#2834

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?
#2857
### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

feat: API access key management
https://github.com/infiniflow/ragflow/issues/2846
feat: Render markdown file with remark-loader
https://github.com/infiniflow/ragflow/issues/2846

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

_Briefly describe what this PR aims to solve. Include background context
that will help reviewers understand the purpose of the PR._

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

add api of tenant app

### Type of change
- [x] New Feature (non-breaking change which adds functionality)