Add time booking component

[Syndesi]

Time booking component should be able to work with the following properties, and ideally work with a subset of them and calculate remaining properties automatically:

• Start timestamp.
• End timestamp.
• Duration, calculated property.
• Name.
• Description / summary.
• List of tags, optional.
• Link to other element, usually project or ticket, to which the time is billed.
• State which displays if the time booking is accepted?
  • Can this be resolved with tags?

Timestamps are internally stored as an UTC timestamp, displayed as date + time + user's current timezone in respect with summer/winter time.

• User should be able to define the displayed timezone, either globally or for the component only.