Adding inspection engine

[nyamsprod]

This PR introduces a Inspection engine to try to infer the CSV schema a quick usage will be more useful than a long text:

<?php

declare(strict_types=1);

use League\Csv\Schema\Inspector;
use League\Csv\Schema\EnumField;
use League\Csv\Schema\RegexpField;
use League\Csv\Schema\FieldList;
use League\Csv\Reader;

require __DIR__ . '/vendor/autoload.php';

enum Gender
{
    case M;
    case F;
}

$doc = <<<DOC
name;age;city;id;sexe
Alice;25;New York;3391f7c0-d059-4e90-a73a-14f3140c6870;F
Bob;30;London;;M
Charlie;20;Berlin;3391f7c0-d059-4e90-a73a-14f3140c6870;R
David;35;Paris;42fe384c-9dab-483c-b8e2-44c73a5e9043;F
Frank;40;Tokyo;42fe384c-9dab-483c-b8e2-44c73a5e9043;
DOC;

$fields = FieldList::default()
    ->append(
        RegexpField::uuid(.5),
        new EnumField(Gender::class, .6)
    );
$inspector = Inspector::default()->withFields($fields);

$document = Reader::fromPath('data://text/csv;base64,' . base64_encode($doc));
$document->setHeaderOffset(0);
$document->setDelimiter(';');
$schema = $document->inferSchema($inspector);

$column = $schema->get('age');
var_dump(
    $column->type(), // FieldType::Numeric
    $column->name(), // 'numeric'
);

$column = $schema->get('id');
var_dump(
    $column->type(),            // FieldType::StructuredString
    $column->name(),            // 'uuid'
    $column->metadata->all(),   // ["regexp" => "/^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i"]
);


foreach ($document->inferRecords($inspector) as $record) {
    // the $record values are cast according the the 
    // schema info or null is returned if the raw data can not be parsed.
}

This is a work in progress, feedback and criticism are welcomed!!