Update to new Catalyst API

[kaandocal]

Add support for named parameters, variables etc... - might require rewriting some of the code generation.

[TorkelE]

The Catalyst v16 update (where we move to the new ModelingToolkitBase, rather than ModelngToolkit package) is currently underway. The hope is to have to done asap, but hard to know for certain when the actual release will be.

[kaandocal]

It seems like Catalyst's jumpratelaw hasn't really changed, so there might not be any need! It does not use MTK's way of generating functions (e.g. t is the second argument) but I don't see how that would cause issues - for now at least...

[TorkelE]

If we are lucky, things might go very smoothly, fingers crossed! There is a minor thing that need fixing for the release that hopefully get sorted out today, and then there will just be final checks and stuff and then we can release, so hopefully it is out very soon.

[isaacsas]

Catalyst 16 is out now with updates summarized at https://github.com/SciML/Catalyst.jl/blob/master/HISTORY.md. Hopefully it isn't a big deal to update here for it, but let us know if you need any help!