Daily vs seasonal passage

[danStich]

Need: functionality for users to supply seasonal passage efficiencies that we can convert to time-based rates.

Justification: we traditionally think about upstream and downstream passage in terms of seasonal efficiency and most projection models make assumptions about bulk efficiency to simulate effects of dams (habitat access) on populations. The models in shadia use individual-based migration models instead of (state-based) projection matrices. Upstream passage through dams is parameterized as a probability of passage per unit time (e.g. daily rates). This was done to align with how dam passage standards are prescribed and assessed (e.g. telemetry studies).

[danStich]

Implemented as an n-day (seasonal) rate in #49