Ewatercycle-da

- changes to PF inmplementation: only resamples if Neff < N * f_n_particles

- `ensemble.set_state_vector_variables` now allows use of get and set state vector when not usin DA methods

- Adding generate forcing

- Restructuring package: now seperate files for classes which user will edit

- All user installed plugins are now availible by default.
- `.update(assimilate=False)` is now standard when calling `.update()` to match changes from v0.0.2
- Seperate list `KNOWN_WORKING_MODELS_DA` check whether to continue with assimilating.
- small change to `config_specific_actions`, but this is a WIP

_(forgot to tag this properly so its under the tag v0.0.1)_
- upgrade to new version: added support for on the fly for Data assimilation
- You can now call `.update()` without requiring DA support
- This means that any model can use the programmed data structure
- calling `.update(assimilate=False)` will no longer run the DA code
- smaller changes, bug fixes and additions to docs