Fix rounding of deco stops

[jirkapok]

Describe the issue For diver it is easier to follow the plan by Runtime, so user needs rounded values in the dive waypoints table by runtime.

Current behavior Currently we round to minutes only the stop duration, so it causes nice deco stop durations, but still the runtime is precise number.

Expected behavior All scenarios discussed as part of #28. Final implementation: [] Round stops in the algorithm to runtime, dont round the stop duration. [] In shorten view of the waypoints table show the stops in the way the stop is rounded, but also the runtime + stop duration = next runtime. So both are rounded, but only in the UI to be able switch between the detail table and short table.

[marktai]

@jirkapok I made a PR (https://github.com/jirkapok/GasPlanner/pull/46) that only rounds the stop runtimes (not ascents) to minutes.

[jirkapok]

@marktai sure, i have seen, see my comments.

[jirkapok]

concept archived in branch mt--round-runtimes-to-minutes