Implement stage 2 version 4 database migration

[Patowhiz]

Stage 1 version 4 database migration was about making Climsoft Web be able to write data to observation initial as countries tested data entry via forms and manual import.
Stage 2 is about deprecating data ingestion and quality control via desktop as the features are now stable in Climsoft Web. Users of Climsoft Web will now be expected to only use version 4 for products, paper archive and back up.

So for stage 2 migrations, the following needs to be implemented.

• Change writing to V4 database to be to observation final. Preview 1 and 2 have been writing on observation initial because there was no active and validated quality controls. Preview 3 has more and much better QC routines than version 4. So change the saving to V4 database to be only for values that have passed all qc tests in Climsoft Web. This means Climsoft Web will no longer work with observation initial.
• Climsoft Web should only write to observation final when data has been quality controlled.
• Simplify the elements mapping used for importing from V4 database. System should come up with a sensible default.

[Patowhiz]

Once products and database back up are implemented in Climsoft web, stage 3 migration can be initiated. This would mean that Climsoft Web will no longer need to write to the version 4 database or read from it, and the desktop will be used for paper archive.