fix(caldav): grant sharee Acls to the delegate

[hamza221]

• Resolves: Feat/add calendar delegation features calendar#8085 (comment)

Summary

Grant the delegate the same ACLs as the sharee depending on his write or read access

Reproduction

• user 1 shares calendar with user 2 (write or read)
• user 2 delegates to user 3 (Proxy write or read)
• uses 3 access calendar and can (read or write) the calendar shared by user 1

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

AI (if applicable)

• The content of this PR was partly or fully generated using AI

[hamza221]

/backport to stable34

[hamza221]

/backport to stable33

[hamza221]

/backport to stable32