Create schema for storing ensemble transition data

[oyvindeide]

Currently we are saving some data when doing updates, but we are not always saving data indicating how an ensemble is created. We should create a data model for saving ensemble transitions, with information about how an ensemble is created, for example, for es-mda we should store:

• Weights
• Observation scaling factors
• Type of transformation
• Observation report
• Update settings (outlier thresholds, localization settings, etc)

For Everest this would be slightly different, but for most cases it is probably some tables with some metadata.

[yngve-sk]

For EnIF we need to store some matrices, some of which are sparse (may be boiled down to non-sparse more concise datasets which can be used to create the same plots, remains to be seen)

[yngve-sk]

Blocked by https://github.com/equinor/ert/issues/11477 . Moving some info to runmodels will alleviate us from having to store it as "ensemble transition"