Backports for 7.10.6-44 (6280)

Changes

• Defect: Resolving type error on quota check when quickly adding mail attachments, Commit: ead8b4a4
• Fix: Bypassing anti-tracking through external images in plain text mails, Commit: f853986d
• Fix: Appointment details stay open after selecting other calendar week (OXUIB-2713), Commit: 1525663a
• Fix: Plain text mail with inline image contains broken link in mail content, Commit: 05a834e3
• Fix: QR code not generated when using "connecting your device", Commit: a06ffe07

MR

https://gitlab.open-xchange.com/frontend/core/-/merge_requests/1236