Improve Configurability of the Delay Model

Following ADR-88, and an improved understanding of the delay model requirements, the following improvements are proposed to enable the variability in delay model between the mid and low telescope, as well as the ability to set these parameters on a subarray level.

delay_Cadence - the frequency at which the delay model updates are published.

delay_validity_interval - the period for which the published delay model is valid

The mid and low telescope systems could be deployed with a set of default values for these parameters. The need (and priority) to override these parameters at a subarray level, and modifying it at run time, need to be assessed.