feat: enhance exporter architecture with chunked vs full export and context

[disstudio]

Changelog

feat: Pass context into exporter

Add context array with resourceAlias, batchIndex, exportFilename fields, so exporter implementations can perform more complex logic (such as headers, export by template, individual for each resource etc).

feat: Add ability to choose two strategies for exporter

If ExporterInterface::supportsBatchedExport() is true, export() is called multiple times (once for each data chunk). It is suitable for formats like CSV, each export operation can append new data to the file. This strategy has limitations - it requires that the export queue has only one worker to avoid concurrent write to file.
If it is false, all exported data is merged to one array and export() is called once with all collected data. This strategy will consume more memory for large datasets.

feat: CsvExporter can write headers

fix: Possibility to add custom exporters outside the bundle

Removed BatchedExportDataManager::FILE_BASED_FORMATS due to its limitation to internal exporters only.

fix: Unable to export more than one batch

ExportCompletedHandler: iterator_to_array(...$batchedData); replaced by array_merge(...iterator_to_array($batchedData));