Add licensing and copyright information for all files in this repository. This
either happens in the file itself as a comment header or in the file
`.reuse/dep5`.
This commit also adds a Github workflow to check pull requests and adapts
copyright.pl to the changes.
Closes#8869
... and make sure the code never updates 'set.prefer_ascii' as it breaks
handle reuse which should use the setting as the user specified it.
Added test 1569 to verify: it first makes an FTP transfer with ';type=A'
and then another without type on the same handle and the second should
then use binary. Previously, curl failed this.
Closes#6578