Add complex workout to session management

[Abasz]

A small update of my status. I have updated the https://github.com/JaapvanEkris/openrowingmonitor/tree/Backend_Redesign branch, to include more complex workouts, allowing @carlito1979 to change these parameters. Most changes currently are limited to server.js and RowingStatistics.js. I also added a change to the PM5 code in GeneralStatus.js, where I replaced

      bufferBuilder.writeUInt8(255)

with

      // intervalType: UInt8: 1 INTERVALTYPE_TIME, 2 INTERVALTYPE_DIST, 255 NONE
      // ToDo: split down further to allow rest intervals when the PM5 schedule dictates it
      bufferBuilder.writeUInt8(data.sessiontype === 'Distance' ? 2 : (data.sessiontype === 'Time' ? 1 : 255))

I'll run a test this evening and then I'll put everything in a PR for @laberning to include in V1Beta.

There are some ToDo's in this setup which aren't critical:

• Intervals typically are numbered, and RowingStatistics should maintain this. But I need to find out how they need to be numbered in the PM5 reporting, FTMS reporting (?), tcx-files and RowsAndAll csv. Big question is whether we start at 0 or 1.
• tcx files can contain laps. I have absolutely no clue how to change the mapping to get that working. Distance seems to continue regarless of intervals, but timing seems to be interrupted. Perhaps @laberning can help out here in creating lap-objects in the WorkoutRecorder.
• RowsAndAll csv's can include interval information as well, however we report per stroke and an interval can change mid-stroke. So we need to find a way to decently report his there as well. I've already reached out to them to find out how they want to deal with this.

For now, all these outputs will ignore the interval-information in their reporting, but the GUI will respond accordingly. This will allow @carlito1979 to build the PM5 service interface and store the interval data (and use it!), and when we can take the rest from there.

Looking a bit at the architecture and the Interval object, I realize that we omit one possibility that the PM5 really has: a PauseBefore option for each interval. I have some ideas, but I will not get around to implement them before mid january. We need the RowingStatistics to manage this information (allowing a countdown timer on the display and setting the correct session and interval state), but I need to find out how this interacts with the PM5 code, and integrate that in @Abasz his code.

I moved this to a separate discussion to keep better track of different topics

[JaapvanEkris]

Good idea, although it is related to @carlito1979 's improvements of the PM5 interface. I created a PR, so the approach should be visible to all now.

[JaapvanEkris]

I created a new (cleaner) pull request for this (see PR #114). In https://github.com/JaapvanEkris/openrowingmonitor/blob/v1beta_updates/app/server.js, I've added an example structure for the PM5 to generate. Please note, this needs to be passed to rowingStatistics by calling rowingStatistics.setIntervalParameters(intervalSettings), but the trigger to do that (i.e. the PM5 telling server.js that there is a workout) isn't known to me yet, so that is identified as a ToDo.