Release v0.10 - Required changes

[JulStraus]

The following list provides an overview of the individual things that must be removed when moving to version 0.10:

• Remove the function variables_capex including its call in create_model.
• Switch to constraints_ext_data from constraints_data for all create_node functions.
• Remove the function create_link(m, l::Link, 𝒯, 𝒫, modeltype::EnergyModel).
• Remove the function constraints_data(m, n::Node, 𝒯, 𝒫, modeltype::EnergyModel, data::ExtensionData).
• Remove all legacy constructors in src/legacy_constructor.jl and ext/EMIExt/structures/legacy_constructor.jl. We introduced them quite a while ago and I think after 1 year, it is reasonable to remove them, especially given the major changes related to the model since these versions (Version 0.6 to 0.9 in EMB and 0.5 to 0.8.1 in EMI).