[WIP] Handle dict syntax in state trigger "for"

[emlove]

Description

Our for configuration in our state trigger currently supports any of the following formats. This PR adds client handling to convert the dict format into string format so it can be rendered and edited in a single text field.

for: 30 # seconds
for: '2:15:30' # 2 hours, 15 minutes, 30 seconds
for:
  hours: 2
  minutes: 15
  seconds: 30

Questions

1. Should we even support loading this syntax in the frontend? It'll only be present for converted automations. If not, should we deprecate this syntax, since it's functionally equivalent with the string syntax. It also seems confusing, since it appears very similar to the time interval trigger configuration, but behaves differently, since we're only declaring a delay time, instead of a periodic interval.
2. If we do want to support this, we'll need to roll it out to numeric_state as well, so maybe there's somewhere better for this logic to live, or maybe it should even be converted in the backend view.

[balloob]

I think that converting to string format is good 👍

[balloob]

I can't remember why we support the dict format btw 🤔

[balloob]

Ah the implementation is that the dict format is just passed as keyword args to the timedelta constructor.

[balloob]

Make sure to add padStart polyfill to compatability.js