URL-provided signals are given a title in the left-side panel based on their parameters (data source, signals, daily/weekly cadence etc.)
Added support for COVIDCast signals with a weekly cadence. This is based on the time_type specified in the meta endpoint, and works for both URL-provided signals as well as those selected in the signal picker.
Closes #43, partially addresses #42:
time_type
specified in the meta endpoint, and works for both URL-provided signals as well as those selected in the signal picker.