Pull Request Description

330

First step towards uncertainty quantification in HERON.

This introduces a new ValuedParam called RandomVariable (to the user, this is referred to as uncertainty).
Users can select this ValuedParam as the input for any driver, reference_price, reference_driver, or scaling_factor_x of a component's cashflow
- this takes the form of an <uncertainty> node in the HERON XML
- within that node, the user can provide any one of the Distributions classes outlined in RAVEN (https://github.com/idaholab/raven/blob/devel/ravenframework/Distributions.py)
- Internal checks automatically tell the user if required subnodes/attributes/parameters are missing
template_driver.py has been updated to:
- write these Distributions to the inner.xml automatically
- add the "uncertain" parameters as variables to the MonteCarlo sampler so they are sampled alongside the TSA/ARMA ROM for each inner realization in RAVEN-runs-RAVEN

NOTE: this does not currently work with StaticHistories (CSV) inputs.

The following review must be completed by an authorized member of the Change Control Board.

[x] 1. Review all computer code.
[x] 2. If any changes occur to the input syntax, there must be an accompanying change to the user manual and xsd schema. If the input syntax change deprecates existing input files, a conversion script needs to be added (see Conversion Scripts).
[x] 3. Make sure the Python code and commenting standards are respected (camelBack, etc.) - See on the wiki for details.
[x] 4. Automated Tests should pass.
[x] 5. If significant functionality is added, there must be tests added to check this. Tests should cover all possible options. Multiple short tests are preferred over one large tes.
[x] 6. If the change modifies or adds a requirement or a requirement based test case, the Change Control Board's Chair or designee also needs to approve the change. The requirements and the requirements test shall be in sync.
[x] 7. The merge request must reference an issue. If the issue is closed, the issue close checklist shall be done.
[x] 8. If an analytic test is changed/added, the the analytic documentation must be updated/added.
[x] 9. If any test used as a basis for documentation examples have been changed, the associated documentation must be reviewed and assured the text matches the example.