REplace the "speed" controle with "rate iteration (Hz)"

[alx-s]

As a user, I want to set the iteration rate of the processors precisely in Hertz. (as opposed to the opaque speed parameter)

Criteria

• replace the "speed" parameter with "iteration rate (Hz)"
• have the associated number box set the rate of the generator between 0Hz and 60Hz

[netherwaves]

(mirrored from Slack thread)

right now the "Speed" field is hardcoded in the QML code; it's not generated from a JSON file like, say, the inhibitory portion of the SNN or the rule # of the WCA, which means that it has the same label value, min/max range and unit for all generators. i've deliberately introduced that change at some point in an earlier sprint because it became apparent to me that, from a strictly UX perspective, all implementations of this parameter would have similar cell matrix feedback responses across all possible algorithms in that they all manipulate time. so it felt natural to me (and that's perhaps a source of bias from personal experience; truthfully i don't know if this is a sentiment shared with anyone here, though i suspect it isn't) to try and ensure that the field would remain consistent in its presentation and front-to-back effects, so as not to further confuse the user by introducing GUI disparities.