Add "Copy Item" functionality

[alexsb]

We want to be able to copy items; ideally if you copy an item or multiple items you get a table into your clipboard with all visible column labels and the items/columns that are currently selected.

This should probably be in a table-compatible format, so that the result would be similar to when I copy from a google sheet.

There could be a global "copy" button, or there could also be an item-specific copy-button, e.g., next to the selection column.

This should also be hooked up to shortcuts (Cmd/Ctrl & C), and expose this to wrapping applications.

[sgratzl]

notes:

lineup has the feature to export the ranking as CSV (https://github.com/lineupjs/lineupjs/blob/main/src/provider/utils.ts#L336). This would be an extension / subset of it by only converting a subset of the rows (e.g. selected row, selected rows, ...) and using the https://developer.mozilla.org/en-US/docs/Web/API/Clipboard_API to copy it into the clipboard

[sgratzl]

see also #510 which adds ctrl-c, ctrl-v for selected rows

[sgratzl]

didn't #510 fixes this issues?