[WIP] fix(DataGrid): Allow columns with empty titles to be used in DataGrid

[ErdaradunGaztea]

Fixes: #1844

The issue stems from the fact that TanStack uses column headers to create unique IDs, and an empty string is not a valid ID. Thus, my solution is to create a unique ID for the column with an empty header. Truth be told, there's no particular reason not to assign IDs equal to their corresponding headers for all the other columns, other that trying to change as little as possible.

Finding a unique ID is done through findUnusedColumnName() which was somewhat inspired by how {tibble} solves column name issues. In this case, the algorithm appends a space until it arrives at a string that doesn't exist in the list of column names. Again, the choice of space is arbitrary. What is important though is to keep in mind that this approach will fail if there is more than one column with an empty name. However, DataGrid currently doesn't work with duplicated names anyway, and generating unique IDs for all columns would probably be the solution.

Side note, I suspect that these large diffs in JS files are due to me using Windows, though I made sure that the output doesn't replace any LF with CRLF.

[schloerke]

If the tanstack id is only browser specific, then this is great.

If the id is used for updates to the server (ex column sorting input values), then we should raise an error server-side before it is even sent to the browser as the column names will not match.

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Narwhals has a restriction of non-duplicated column names. It's fair if we add non-empty column names for tanstack.

[schloerke]

Can we move initName into the function as this will only hold true if the initName is " ".

If other column names can be expanded, then they could both resolve to the same " " string.

However, if we know that "" is the only one being expanded and there are no duplicate names, then this function is only called once... which is safe.

Changing to something more specific...

Suggested change

	function findUnusedColumnName(columns: ReadonlyArray<string>, initName = " "): string {
	function emptyColumnNameToId(columns: ReadonlyArray<string>): string {
	let initName = " ";