feat(ui): 🎉 Add import and merge database feature

- Introduce a new screen for importing and merging database schemas.
- Implement merge logic to combine schemas, tables, columns, and other objects.
- Add options to skip specific object types during the merge process.
- Update main menu to include the new import and merge option.

cmd/relspec/root.go

@@ -22,4 +22,5 @@ func init() {
 	rootCmd.AddCommand(scriptsCmd)
 	rootCmd.AddCommand(templCmd)
 	rootCmd.AddCommand(editCmd)
+	rootCmd.AddCommand(mergeCmd)
 }