fgetcsv(): $escape parameter deprecation notice breaks CSV import via AJAX

Problem/Motivation

When uploading a CSV file to a Chart paragraph via the "Import Data from CSV" feature, an AJAX parsererror (HTTP 200) occurs and the data is not imported. The root cause is a PHP deprecation notice emitted by fgetcsv() in ChartDataCollectorTable.php, which is rendered into the response body before the JSON payload, causing the AJAX handler to fail to parse the response.

On a second upload attempt (with an empty data table), the corrupted form state can cause an unrelated component to be inserted erroneously.

The deprecation notice reads:
Deprecated: fgetcsv(): the $escape parameter must be provided as its default value will change in .../charts/src/Element/ChartDataCollectorTable.php on line 476

This affects environments where PHP deprecation notices are rendered (e.g. development environments or servers with display_errors on), and will become a hard error in a future PHP version.

Steps to reproduce

1. Create a node with a Chart paragraph
2. In the Chart field, open the "Import Data from CSV" section
3. Upload a valid CSV file and click "Upload CSV"
4. Observe the browser console — an AJAX HTTP error with StatusText: parsererror is logged
5. The chart data table fields remain empty

Expected behaviour:
The CSV data is parsed and populated into the chart data table fields without error.

Actual behaviour:
The AJAX response fails with a parsererror due to the PHP deprecation notice being prepended to the JSON response body. On a second upload attempt the form state is corrupt and an unrelated component may be inserted.

Proposed resolution

In src/Element/ChartDataCollectorTable.php line 476, explicitly provide the $enclosure and $escape arguments to fgetcsv():

  -      while ($row = fgetcsv($handle, 0, $separator)) {
  +      while ($row = fgetcsv($handle, 0, $separator, '"', '\\')) {

This matches the historical defaults and silences the deprecation notice in PHP 8.1+, restoring correct AJAX behaviour.