fix(datetime): allow header to render in all wheel picker presentations

[amandaejohnston]

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
  • Some docs updates need to be made in the ionic-docs repo, in a separate PR. See the contributing guide for details.
• Build (npm run build) was run locally and any changes were pushed
• Lint (npm run lint) has passed locally and any fixes were made for failures

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

Presentations time, month, month-year, and year do not currently render the header, even if showDefaultTitle is set to true or something is provided in the title slot. While the original intention may have been to avoid showing the header for wheel pickers, it is currently possible to enable this in other presentations using the preferWheel property.

Issue URL: Resolves #26600

What is the new behavior?

The header now renders in those presentations if enabled. Note that the currently selected date is not shown, since these presentations don't involve selecting specific date(s).

Does this introduce a breaking change?

• Yes
• No

Other information

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[liamdebeasi]

Changes look good. We may want to rename renderCalendarViewHeader since it's no longer specific to the calendar layout. Maybe renderHeader would do? We already have a renderFooter method.

[sean-perkins]

Ditto on the rename for the render function. Nice work here!