Single Owner with time series PPA price multipliers

See this forum post for a description and example file: https://sam.nrel.gov/forum/forum-general/3569

Also, https://sam.nrel.gov/forum/forum-general/3718

Verify that solution works for all financial models that use PPA price multipliers.

Additional send-to-Excel with Equations issues to fix:

• Fix sign of Total IBI and Total CBI under investing activities for all spreadsheets.

• Fix LCOS rows in cash flow.

• Land lease operating expense for FOM financial models

• Fix annual energy to grid/from grid/net

• Test for all financial models

• Fix electricity purchases per Removed self-consumption from PPA revenue section of Cashflow, moved to Electricity purchase #785