feat(timepicker): Support for seconds

[6apc1k]

Feature Description

Currently, the timepicker only allows selection of hours and minutes. It would be beneficial to also support selection of seconds, optionally enabled via an opt-in flag.

Use Case

Dealing with time-sensitive data, such as log viewers, monitoring tools, or scheduling systems. The lack of support for seconds prevents from adopting the Material timepicker for such applications.

[crisbeto]

This should be possible already by providing a custom MAT_DATE_FORMATS.