Markers on zero points

[dev3225]

User story

1. As a user
2. I need markers plotted on the signal whenever there is a zero point
3. So that I can differentiate positive and negative side.

Acceptance criteria

• Markers plotted exactly at the intersection point to the zero line of each signal(channel).
• Marker should be visible to the user as a shaded circle.
• It should be of diameter larger than the thickness of the signal.

Definition of done (DoD)

• Application compiles successfully
• Code is documented
• Feature/Bug/Change is tested by at least one unit or e2e test
• Tests have been passed without warnings (except "deprecated" warnings)
• Changes have been reviewed
• PR has been merged to dev branch
• New dependencies have been added to bill of materials
• Software architecture diagram has been updated
• All acceptance criteria are fulfilled
• Screenshot is attached to issue

DoD general criteria

• Feature has been fully implemented
• Feature has been merged into the mainline
• All acceptance criteria were met
• Product owner approved features
• All tests are passing
• Developers agreed to release

[PhlppKrmr]

As mentioned in the sprint planning, move logic/implementation to backend and compute zero crossings there (else we might run into major performance issues).