Fix time format

[yasar-luo]

This is:

• a bugfix
• a new feature

Checklist:

• Changes are covered by unit tests
• Code style is respected
• Commit message explains why the change is made (see https://github.com/erlang/otp/wiki/Writing-good-commit-messages)
• CHANGELOG.md contains a short summary of the change
• Documentation is updated as necessary

Why this change is needed?

relate issue #664
fix time format for duration is incorrect, when use format [h]:mm it should convert to the "total hours:minutes"

[patrickomeara]

Nice work @GreatHumorist

I think this will also fix @ivankruchkoff's issue #446 and @garrettgjb's issue #342 as the time format is no longer being stripped by the color preg_replace

[yasar-luo]

@patrickomeara this is because the color strip code make [h] be stripped, and the time format default replace h as G in date format, which G represent the 24h format in a day, but which you want is the total hours, in excel, the [h] will default convert it to the total hours, but the PhpSpreadsheet have not achieved.

[PowerKiKi]

In the test data I see quite a few missing cases. Most notably for colors, and also for elapsed periods as mentioned here: https://support.office.com/en-us/article/format-numbers-as-dates-or-times-418bd3fe-0577-47c8-8caa-b4d30c528309.

Would you mind adding those ?

[patrickomeara]

I can add some test cases.

@GreatHumorist are you able to resolve the conflicts via rebase or merge first?

[PowerKiKi]

@patrickomeara feel free to open a new PR based on this one if @GreatHumorist does not reply

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.
If this is still an issue for you, please try to help by debugging it further and sharing your results.
Thank you for your contributions.

[PowerKiKi]

I ended up adding a few cases myself and merged. Thanks !