Add single-layer BigLeafHydraulics Model

[Espeer5]

Purpose

See #599 The existing PlantHydraulics model requires large vectors of data giving the heights of layers in the canopy. This functionality is unused and we have no plans to utilize it in the future. The purpose of this PR is to create a simple plant hydraulics model which is a single stem and leaf compartment, removing the need for that data.

To-do

• Convert all experiments to use BigLeafHydraulicsModel
• Convert all tutorials to use BigLeafHydraulicsModel
• Add a test comparing BigLeafHydraulicsModel to PlantHydraulicsModel
• Validate boundary conditions caught by lai_consistency_check are equal for both models

Content

• BigLeafHydraulics model created implementing same functionality as PlantHydraulicsModel

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• I have read and checked the items on the review checklist.