Moved all configuration customization steps to individual plugins

module/CLI/src/Install/Plugin/ApplicationConfigCustomizerPlugin.php

@@ -0,0 +1,46 @@
+<?php
+declare(strict_types=1);
+
+namespace Shlinkio\Shlink\CLI\Install\Plugin;
+
+use Shlinkio\Shlink\CLI\Model\CustomizableAppConfig;
+use Shlinkio\Shlink\Common\Util\StringUtilsTrait;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Question\ConfirmationQuestion;
+
+class ApplicationConfigCustomizerPlugin extends AbstractConfigCustomizerPlugin
+{
+    use StringUtilsTrait;
+
+    /**
+     * @param InputInterface $input
+     * @param OutputInterface $output
+     * @param CustomizableAppConfig $appConfig
+     * @return void
+     * @throws \Symfony\Component\Console\Exception\RuntimeException
+     */
+    public function process(InputInterface $input, OutputInterface $output, CustomizableAppConfig $appConfig)
+    {
+        $this->printTitle($output, 'APPLICATION');
+
+        if ($appConfig->hasApp()) {
+            $keepConfig = $this->questionHelper->ask($input, $output, new ConfirmationQuestion(
+                '<question>Do you want to keep imported application config? (Y/n):</question> '
+            ));
+            if ($keepConfig) {
+                return;
+            }
+        }
+
+        $appConfig->setApp([
+            'SECRET' => $this->ask(
+                $input,
+                $output,
+                'Define a secret string that will be used to sign API tokens (leave empty to autogenerate one)',
+                null,
+                true
+            ) ?: $this->generateRandomString(32),
+        ]);
+    }
+}