More flexibility for week-type signals

[melange396]

• Building off of Simplified 'No Recent Data' warning logic. #1249, add more flexibility and default handling for signals with a weekly cadence.

At least change this:

www-covidcast/src/modes/summary/Overview.svelte

Lines 36 to 42 in f13c0ec

	...[CASES, HOSPITAL_ADMISSION, DEATHS].map((s) => {
	// As DEATHS sensor is weekly based, we need to add 6 days to the max date of DEATHS sensor to get the last day of the week.
	if (s.name === 'COVID Deaths') {
	return s.timeFrame.max.getTime() + 6 * 24 * 60 * 60 * 1000; // add 6 days to the max date of DEATHS sensor to get the last day of the week.
	} else {
	return s.timeFrame.max;
	}

so line 38 is: if (s.name === DEATHS.name) {
(the current "deaths" dashboard signal is weekly)

...or better yet, do deeper inspection and check the time_type of each of those 3 signals.