branch-3.0: [feature](nereids) support explain command return empty string to test planner performance (#54422)#55038

dataroaring merged 2 commits intoapache:branch-3.0apache/doris:branch-3.0from

924060929:branch-3.0-explain-none924060929/incubator-doris:branch-3.0-explain-noneCopy head branch name to clipboard