Bug fixes

Fix notice from php 7.4

• D9 compatibility
• Refactoring of redundent code parts by introducing base classes and traits for the gateway plugins
• couple of minor fixes and tweaks found along the way
• code cleanup and several CS fixes
• Send a lot more data on (pre)authorization requests, such as cart item data, shipping address, etc
• Allow to choose the hash method
• Activate secure invoice - a separate issue for this will be opened though, as this is untested currently, also still missing some parameters in the actual capture request

Changes since 8.x-5.1:

• Webform 6.x support, aka full D9 support
• #3153254 by dejan0: Composite elements can't be mapped
• #3101911 by a3hill: Invalid argument supplied for foreach() when no custom data

New in 1.0.9:
Make D9 and composer happy, fix some whitespace in the safedelete.info.yml file

Changes in 1.0.8
Support file usage decrement for:
#3186367: File usage increment and decrement for embedded media