[TASK] Document Extbase FileUpload

[garvinhicking]

The first section about the history is "new content".

Starting with "_extbase_fileupload_attribute" the rest is taken from the well-written Changelog entry.

Closes TYPO3-Documentation/Changelog-To-Doc#1040

Note: Needs manual 12.4 backporting to reduce some of the info.

Releases: main, 12.4

[brotkrueml]

Please write "Domain Model" lowercase, like written here:
https://docs.typo3.org/m/typo3/reference-coreapi/main/en-us/ExtensionArchitecture/Extbase/Reference/Domain/Model.html#introduction

Additionally, you wrote sometimes "Domain Model" and sometimes "domain model".

I just checked the first part. The last part I'll do later.

[brotkrueml]

Do you really want to backport it to 12.4? Mostly it is about 13?

[garvinhicking]

Adressed the changes by @derhansen and @brotkrueml

[garvinhicking]

Do you really want to backport it to 12.4? Mostly it is about 13?

A manual backport, yes. I want to keep the first section and then only hint at the v13 change. I didn't have time enough to split this up into a pre-patch because I need this for v13, and the backport ("prepatch") can take longer.

[derhansen]

Really great work 👍 I only added a single comment, that we should note, that domain model nesting is not supported. But this can also be added afterwards.

Further discussion in follow-up, we want to get this wrapped up as a first step to ease discussion