avoid projecting segments below the zero

[XavierFranch]

Course: PES

Project group id: PES-TEACHER

Describe the improvement
In the historical view, when showing the reference segment interpolated from the values, the lowest value shouldn't be lower than 0 (see screenshot below with the problem)

Where Affects
Historical view

Expected behavior
Take 0 as lower value when necessary to avoid segments projecting below 0

Screenshots

Technical context (if it is relevant):
N/A

Additional context
N/A

[jdconejos]

The trendline now stops when the value is below zero, however it can still surpass the upper limit of the graph. This is because of a limitation of the plugin we use to draw the line.