Add ability to not connect null values in 'plot'

[user45876]

Is your feature request related to a problem? Please describe. I am using a Bosch indego Mower at home. I am also using the fabulous HA integration - both for the mower and for my OEPL-Tags - thank you so much :)

Sometimes, the indego mower plot does seem to have null values. Or the plot function only picks up changes in value - I am unsure. Here is a picture, we are talking about the two highlighted graphs, especially about the straight 'jumps' in the left area of both graphs.

Thats the plot part on the drawcustom action:

   - type: plot
      x_start: 105
      y_start: 26
      x_end: 200 
      y_end: 57 
      duration: 43200
      low: 1 
      high: 100 
      ylegend: 
        position: right
        size: 5
      yaxis: 
        width: 2
        color: red
        size: 1
        tick_width: 1
        tick_every: 101
        grid: null
      data:
        - entity: sensor.indego_xxxxx_battery_percentage
          joint: curve
          width: 2

    - type: plot
      x_start: 200
      y_start: 26
      x_end: 296
      y_end: 57 
      duration: 43200
      low: 1
      high: 100
      ylegend:
        position: right
        size: 5
      yaxis: 
        width: 2
        color: red
        size: 1
        tick_width: 1
        tick_every: 101
        grid: 1
      data:
        - entity: sensor.indego_xxxxx_lawn_mowed
          joint: curve
          width: 2

Describe the solution you'd like It would be great to have a corresponding config option to not connect, i dont know, if there are no values for a vertain time or a certain percentage of the graph, maybe.

Describe alternatives you've considered Live with it ;)

Additional context Thank you :)