Make building pulses with fillers easier

[terrorfisch]

Provide tools to easily insert pulses that:

1. Extend a sequence of pulses to a given length
   • Hold previous voltage
   • Hold given voltage
   • Inserted at the front in the middle or at the end
2. Interpolate between previous and next pulse for a given duration using
   • Linear interpolation
   • An arbitrary function

This cannot be implemented by pulse templates as they are now because pulse templates are not context aware i.e. they behave the same independent of their surroundings. I would like to keep it that way.

I think there are two options to implement this. Both include Builder objects that are used like pulse templates during the construction of a pulse. Option 1 is that the builder objects remain in the composing pulse template and behave like pulse templates. This requires that they get their context provided for all actions. Option 2 is to add a dedicated final build step, that replaces all Builder objects with pulse templates.

Option 1 is easier to use because it omits the build step but option 2 is easier to implement and less error prone. I prefer option 2.

• Builders require the initial and final value of arbitrary pulse templates
• Prototype builder class