CalDAV improvements: Calendar directory autodiscover, prefix fix, REPORT method fix

[LuceusXylian]

Sorry for this mess in the git history. Because of a merge between commits I do not know how to squash safely the commits together.

[Copilot]

Pull request overview

This pull request implements several CalDAV improvements to enhance calendar functionality in the dav-server library. The changes focus on automatic calendar directory creation, fixing URI path prefixes, and improving the REPORT method implementation for better CalDAV client compatibility.

Changes:

• Updated all test URIs from /calendar to /calendars/my-calendar to use the standard CalDAV directory structure
• Added automatic creation of the /calendars directory in MemFs and LocalFs implementations
• Refactored REPORT method handling to use PropWriter for consistent XML response generation

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
tests/caldav_tests.rs	Updated test URIs to use /calendars/ prefix and enhanced test assertions with better error messages
src/memfs.rs	Added automatic /calendars directory creation and is_calendar method implementation
src/localfs.rs	Added automatic /calendars directory creation and is_calendar method implementation
src/localfs_macos.rs	Added stub is_calendar method implementation
src/handle_props.rs	Added is_calendar checks and CalDAV namespace handling, made PropWriter public for reuse
src/handle_caldav.rs	Refactored response generation to use PropWriter and improved calendar multiget handling
src/fs.rs	Added is_calendar trait method to DavMetaData
src/caldav.rs	Added default CalDAV directory constants, fixed element naming with prefixes, and improved helper functions
examples/caldav.rs	Switched from MemFs to LocalFs and added request logging middleware
README.CalDAV.md	Updated documentation to reflect new directory structure and setup requirements
Cargo.toml	Updated hyper-util dependency from 0.1.2 to 0.1.19 and bumped version to 0.10.0

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[Copilot]

In the calendar query handler, items that don't match the query filter are being added to the missing_hrefs list and will be reported with 404 Not Found status. This is incorrect behavior - calendar items that don't match the query filter should simply be excluded from the response, not reported as missing. The missing_hrefs should only be used for items that are requested but don't exist.

Suggested change

	// Not found
	missing_hrefs.push(item_path.to_string());