Adds support for Seconds to TimePicker

[begleysm]

What does the pull request do?

This PR adds support for Seconds to the TimePicker Control (which currently only supports Hours and Minutes). It adds a UseSeconds Property which defaults to false. It addresses a need being tracked in Issue #12045.

What is the updated/expected behavior with this PR?

Usage of existing TimePicker Controls should see no change since the new UseSeconds Property is optional and defaults to false which results in the TimePicker behaving just as it did before.

How was the solution implemented (if it's not obvious)?

I first went through and added the Seconds column by finding all of the references to Minutes and duplicating their behavior. I expanded the PickerHosts, TextBlocks, Dividers, etc and updated the ClockIdentifier column to be to the right of the new Seconds column. I then went through and found all of the references to ClockIdentifier and use it as a template on how to show/hide the new Seconds column based on my new UseSeconds property. Everywhere possible I tried to use naming consistent with the existing parameters. I also updated the DateTimePickerPage of the ControlCatalog to demonstrate the new UseSeconds feature. I added a updated one of the Unit Tests and added a Unit Test.

Checklist

• [ X ] Added unit tests (if possible)?
• [ X ] Added XML documentation to any related classes?
• [ will do when PR is accepted ] Consider submitting a PR to https://github.com/AvaloniaUI/avalonia-docs with user documentation

Breaking changes

None

Obsoletions / Deprecations

None

Fixed issues

Fixes #12045

Example Screenshot

[avaloniaui-bot]

You can test this PR using the following package version. 11.2.999-cibuild0049181-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[cla-avalonia]

• All contributors have signed the CLA.

[begleysm]

@cla-avalonia agree

[begleysm]

@cla-avalonia agree

[jmacato]

Overall looks good to me! Thank you for your contribution!

cc @maxkatz6 @grokys