[BUG] Extension settings are not accessed correctly

[beatrycze-volk]

Description

The extension configurations are accessed in the FlexForm settings array.

Examples:
$this->settings['forceAbsoluteUrl']
$this->settings['fileGrpScore']

Reproduction

Steps to reproduce the behaviour:

1. Install TYPO3 11.x with PHP 8.x
2. Click on link to display document page e.g. https://sachsendigital.ddev.site
3. See error

Expected Behavior

The extension configurations should be accessed as the extension configuration, so for the examples above it should be:
$this->extConf['general']['forceAbsoluteUrl']
$this->extConf['files']['fileGrpScore']

Screenshots and Examples

Environment

• RDBMS version: MariaDB 10.3
• TYPO3 version: 11.5.37
• PHP version: 8.2

[sebastian-meyer]

This is a duplicate of #1325, isn't it?