[Store] Add CSV loader to load data from CSV file as text documents

[RamyHakam]

Q	A
Bug fix?	no
New feature?	yes
Docs?	no
Issues	----
License	MIT

This PR adds a new CsvLoader class to the Store component for loading documents from CSV files. Each row in the CSV becomes a TextDocument, with configurable column mappings for content, ID, and metadata.

Features:

• Configurable content column (by name or index)
• Optional ID column mapping (generates UUID if not specified)
• Metadata columns extraction
• Custom delimiter, enclosure, and escape characters
• Header row support (enabled by default)
• Runtime options override via load() method
• Automatic skipping of empty content rows
• Proper handling of quoted content with commas and embedded quotes

Usage example:                                                                                                                  
$loader = new CsvLoader(                                                                                                        
    contentColumn: 'content',                                                                                                   
    idColumn: 'id',                                                                                                             
    metadataColumns: ['author', 'category']                                                                                     
);                                                                                                                              
                                                                                                                                
foreach ($loader->load('/path/to/data.csv') as $document) {                                                                     
    // $document is a TextDocument with content, ID, and metadata                                                               
}                    

[chr-hertel]

isn't it the same like:

Suggested change

	$value = $this->getValue($data, $column);
	$value = $data[$column] ?? null;

[RamyHakam]

Ya, this is simple
Fixed

[chr-hertel]

Thanks for working on this - good one 👍