Prevent undefined array key "format" in CurrencyViewHelper.php

[h-e-l-l-o-w-o-r-l-d]

When updating from 10.2.4 to 10.3.0 this warning occurred in the cart backend module on folders with orders.

Same as #556.

PHP Warning: Undefined array key "format" in /var/www/typo3/vendor/extcode/cart/Classes/ViewHelpers/Format/CurrencyViewHelper.php line 105

[extcode]

I think you use Site Sets to configure your site.
In this case the ext_typoscript_setup.typoscript will be ignores (see: https://docs.typo3.org/m/typo3/reference-coreapi/main/en-us/ExtensionArchitecture/FileStructure/ExtTyposcriptSetupTyposcript.html)

This file configures module.tx_cart in instances with TypoScript site configuration.

This causes the error of a missing configuration. I'll have a look how to set up modules via Site sets. In next major release most of TypoScript settings will be migrated to Site sets by default.

[extcode]

I think we can move the block from this file to pagets.typoscript. Should look like:

tx_cart {
    settings {
        format.currency {
            currencySign       = {$plugin.tx_cart.settings.format.currency.currencySign}
            decimalSeparator   = {$plugin.tx_cart.settings.format.currency.decimalSeparator}
            thousandsSeparator = {$plugin.tx_cart.settings.format.currency.thousandsSeparator}
            prependCurrency    = {$plugin.tx_cart.settings.format.currency.prependCurrency}
            separateCurrency   = {$plugin.tx_cart.settings.format.currency.separateCurrency}
            decimals           = {$plugin.tx_cart.settings.format.currency.decimals}
        }

        backend {
            dateFormat = {$plugin.tx_cart.settings.backend.dateFormat}
        }
    }
}