NHLIB Integration: Add 'intermediate data' DB shard

[Lars Butler]

'intermediate data` (idata) -- for storing intermediate calculation results

When a calculation completes, this data can be purged. While a calculation is in progress, workers will fetch and update this data.

idata.lt_realization:
  - hazard_calculation_id
  - ordinal (aka, the logic tree sample number)
  - sm_lt_path
  - gsim_lt_path
  - seed
  - is_complete
  - total_sources
  - completed_sources (note: when completed_sources == total_sources, is_finished = true)

idata.source_progress:
  - lt_realization_id
  - parsed_source_id
  - is_complete

idata.hazard_curve_progress
  - lt_realization_id
  - result_matrix

idata.site_data
  - lons
  - lats
  - vs30
  - vs30_type
  - z1pt0
  - z2pt5