refactor: replace skill code with skill ID across the application

- Updated skill handling to use skill IDs instead of skill codes in various components, services, and models.
- Modified tests to reflect changes in skill identification.
- Removed references to skill codes in favor of skill IDs for consistency and clarity.
- Updated localization files to remove skill code references and adjust error messages accordingly.

internal/handlers/dashboard/skill_definition_handler.go

@@ -28,7 +28,6 @@ func SkillDefinitionAnyList(ctx *gin.Context) {
 	cnd := params.NewPagedSqlCnd(ctx,
 		params.QueryFilter{ParamName: "status"},
 		params.QueryFilter{ParamName: "name", Op: params.Like},
-		params.QueryFilter{ParamName: "code", Op: params.Like},
 	).Desc("id")
 	if _, ok := params.Get(ctx, "status"); !ok {
 		cnd.Where("status <> ?", enums.StatusDeleted)