part of the 0-value issue

1. try and generate time sequence through psql's internals and compare to BuildFrames output; if satisfactory we could do this using an in-band migration
2. if this isn't; we can do this using an oob migration:

• construct the recording times for the historical data according to BuildFrames (12 points only)
• fetch unique recording times for series points (additional points)
• add this data to insight_series_recording_times

/cc @Joelkw @felixfbecker @vovakulikov