Rewrite share expiration date field's date handling, fixing issues

[claucambra]

Rather than deal with messy dates and times (and timezones) using JS dates in QML, this PR moves the inner workings of the date input field into a C++ class using QDates, fixing lots of issues on this front.

Fixes #5627
Fixes #5495

[claucambra]

/backport to stable-3.9

[codecov]

Codecov Report

Merging #5961 (c01b669) into master (2dc3af2) will decrease coverage by 0.04%.
The diff coverage is n/a.

❗ Current head c01b669 differs from pull request most recent head 774918c. Consider uploading reports for the commit 774918c to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5961      +/-   ##
==========================================
- Coverage   60.14%   60.11%   -0.04%     
==========================================
  Files         145      145              
  Lines       18872    18872              
==========================================
- Hits        11351    11344       -7     
- Misses       7521     7528       +7     

see 2 files with indirect coverage changes

[sonarqubecloud]

SonarCloud Quality Gate failed.   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
4 Code Smells

0.0% Coverage
0.0% Duplication

The version of Java (11.0.14.1) you have used to run this analysis is deprecated and we will stop accepting it soon. Please update to at least Java 17.
Read more here

Catch issues before they fail your Quality Gate with our IDE extension SonarLint

[claucambra]

/backport to stable-3.10

[mgallien]

we need automated tests for DateFieldBackend otherwise, it is complicated to predict the behavior

[claucambra]

we need automated tests for DateFieldBackend otherwise, it is complicated to predict the behavior

Added automated tests now

[nextcloud-desktop-bot]

AppImage file: nextcloud-PR-5961-774918c5d124f0fa6c6f3b3a3c26f4d9892cdb93-x86_64.AppImage

To test this change/fix you can simply download above AppImage file and test it.

Please make sure to quit your existing Nextcloud app and backup your data.

[sonarqubecloud]

SonarCloud Quality Gate failed.   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
4 Code Smells

86.4% Coverage
0.0% Duplication

Catch issues before they fail your Quality Gate with our IDE extension SonarLint

[claucambra]

/backport to stable-3.10

[backportbot-nextcloud]

The backport to stable-3.10 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable-3.10
git pull origin stable-3.10

# Create the new backport branch
git checkout -b fix/foo-stable-3.10

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts. Resolve them.
git cherry-pick abc123

# Push the cherry pick commit to the remote repository and open a pull request
git push origin fix/foo-stable-3.10

More info at https://docs.nextcloud.com/server/latest/developer_manual/getting_started/development_process.html#manual-backport

[krwi]

Thank you so much, @claucambra and @mgallien! ❤️