Improvements

Some ideas to further improve the timer after the German national youth competition in Bexbach.
- [x] Remove seconds in clock
- [ ] Start time input has no seconds on IOS (maybe [this solution](https://stackoverflow.com/questions/14487621/how-do-i-force-seconds-to-appear-on-an-html5-time-input-control))
- [x] Change time input to separate fields for hours:minutes:seconds
- [x] Changes to `pre_start_behaviour`:
- [x] make it a dropdown instead of a tick (#27)
- [x] remove `ShowZero` (#26)
- [x] add `ShowFirstInterval` (#26)
- [x] add `ShowLastInterval` (#23)
- [x] Separate configuration and control -> `/manage/` should not have any configuration. Only show the current timer and the buttons restart, pause/resume and "configure"
- [x] ~~Add option to count up (per segment)~~
- [ ] Change from `duration` and `count_to` to `from` and `to` => this will also allow counting up, but will be a breaking change 🚧
- [x] Refactor `calculateNewStartAt` and properly define the behavior on changes
- [x] Add option to skip current segment
- [x] Add option for "start signal" that runs when the timer is started (#23)
- [x] Add template for Worldcup Quali (5min+15s)
- [ ] Add an id to the websocket get time command which will be set by the client and sent back by the server
- [ ] make frontend controls configurable
- [ ] for the 4min + wait, it should be easier to understand what button does what
- [ ] hide time options behind advanced setting to make it easier to configure
- [ ] add verifier which shows something like "compliant for ifsc final"
- [ ] add option to override color with get parameter (maybe use `bgcolor` and `fgcolor` to make @baycom happy... https://github.com/baycom/nodeclock/blob/b279e096f4e6fd774f715199bbec4398708f9c0b/public/js/timer.js#L481C2-L481C9)
- [ ] fix high cpu usage
- [ ] when a sound is playing and the start_at time changes, the sound should be stopped