Feat: Initialize context engine CLI (#13776)

### What problem does this PR solve?

- Add multiple output format to ragflow_cli
- Initialize contextengine to Go module
  - ls datasets/ls files
  - cat file
  - search -d dir -q query

issue: #13714

### Type of change

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

internal/cli/user_parser.go

@@ -1,6 +1,9 @@
 package cli
 
-import "fmt"
+import (
+	"fmt"
+	"strconv"
+)
 
 // Command parsers
 func (p *Parser) parseLogout() (*Command, error) {