feat!: ✨ fixes issue #267. show 0 hr and 24 hr markers in timeline.

[ParthBaraiya]

Description

Added support to show end hours i.e. 0 hr and 24 hr marker in DayView and WeekView.

Checklist

• The title of my PR starts with a [Conventional Commit] prefix (fix:, feat:, docs: etc).
• I have followed the [Contributor Guide] when preparing my PR.
• I have updated/added tests for ALL new/updated/fixed functionality.
• I have updated/added relevant documentation in docs and added dartdoc comments with ///.
• I have updated/added relevant examples in examples or docs.

Breaking Change?

• Yes, this PR is a breaking change.
• No, this PR is not a breaking change.

Migration instructions

Updated syntax for timeStringBuilder and timeLineBuilder in DayView and WeekView.

// Old
DayView(
    ...,
    timeStringBuilder: (date) => "",
    timeLineBuilder: (date) => SizedBox(),
);

// New
DayView(
    ...,
    timeStringBuilder: (time, date) => "",
    timeLineBuilder: (time, date) => SizedBox(),
);

We have introduced a new parameter, TimeOfDay, to represent time in 24-hour. Using DateTime for this purpose was inconvenient, as setting the hour to 24 would change the day and reset the hour to 0. The TimeOfDay parameter avoids this issue and provides a straightforward way to handle 24-hour time representations. Users who need to work with day, month, or year can still use the DateTime parameter as needed.

Related Issues

Closes #267