Review and improve logic for reading cycle delays

[ZavenArra]

We want to separate the concepts 'delay' and 'interval' in our code and documentation

A delay is a time period that takes place between the end of a process and the start of another process
An interval is a time period that takes place between the start of a process and the next iteration of the same process

As we process measurement cycles, the following shall be intervals

• The time between each wake to begin measuring
• The time between each burst
• The time between each newly available reading on a sensor

And the following shall be delays

• The global start up delay for the measurement cycle
• The start up delay for each sensor

[jakehosen]

Not causing a problem but still needs to be corrected to work properly.

[ZavenArra]

I think we could consider calling 'start up delay' as 'start up interval' as well, which could express that all the configured start up delays start from the relevant setup completion time.

Global start up delay starts from completion of all sensor setup.
Individual sensor start up delay starts from the completion of setup for that particular sensor.