Data Grid Find And Replace

Find-and-replace add-on for the gridcn data grid: useDataGridFindReplace returns a plugin that adds a panel (Mod+F finds, Ctrl+H replaces) sharing the quick search, with match case and whole cell options. Replace and Replace all write through each column's text codec and validation as one undoable change; planReplace is the pure planner behind them. Strings live under labels.findReplace.