Add templates into cards

[mainmind83]

This function would allow, for example, to use helpers as the source of the dates of the statistics cards

type: statistic
entity: sensor.consumo_casa_kwh
stat_type: change
name: Casa
period:
  fixed_period:
    start: "2024-12-16"
    end: "2025-01-16"

with something like:

start: states('input_datetime.start_date')

I have not found a previous request...

[karwosts]

While not directly what you asked for, I did add ability to dynamically select the time range of statistic card (coming 2025.3)

#23794

[mainmind83]

Power panel is much improved, could be a workaround, although inclusion on cards will allow for more customizations