Merge branch 'hotfix/3.1.5'
Do not add news and event URLs to the sitemap if the target page is exempt from the sitemap (see #6418)
URL decode image paths when exporting to PDF (see #6411)
Use a closure instead of `nl2br_callback`
Fix the phpDoc blocks of the library classes
Set the correct empty value depending on the database field type (see #6424)
Support UUIDs in various `FilesModel` methods to be backwards compatible
Fix some wrong namespace usages of the `Validator` class (see #6429)
Support CSS selectors up to 1022 charachters long (see #6412)
Add the missing "sqlGetFromDca" hook (see #6425)
Support sorting in list mode without selecting a position (see #5802)
Fix a code formatting issue in `DC_Table::getNewPosition()`
Correctly generate HTTPS URLs in the sitemap (see #6421)
Apply the sitemap exemption logic to FAQs and newsletters, too (see #6418)
Remove a redundant argument from `tl_files:checkFilename()`
Fix a wrong variable name in the `FromSelectMenu` class (see #6431)
Fix a wrong phpDoc description
Fix a comment in the database updater
Correctly protect newly created folders (see #6432)
Correctly show the folder protection status in the file picker (see #6433)