Hydrogen improvements

[kndehaan]

Modelling of hydrogen supply, demand and storage has been improved. Summarised:

• A break down in must-run and dispatchable plants of the hydrogen supply technologies ATR, SMR and ammonia reforming
• Possibility to change the merit order of dispatchable hydrogen production and demand
• Modelling of hydrogen storage is improved by adding salt cavern and depleted gas field technologies and allowing the user to set installed volume and relative capacity.
• Changes in hydrogen transport assumptions and modelling
• New charts: "Installed storage volume per carrier" and "Flexible hydrogen supply and demand per hour"

Changes applied in this repo specifically are:

• Required changes to make modelling of hydrogen merit instead reconciliation
• Allowing hydrogen_output_capacity on nodes

Goes with:

• https://github.com/quintel/etsource/pull/3021
• https://github.com/quintel/etmodel/pull/4223
• https://github.com/quintel/documentation/pull/175
• https://github.com/quintel/etdataset/pull/994
• https://github.com/quintel/atlas/pull/166
• https://github.com/quintel/etengine/pull/1421