FR: Move Patcher Management to a top level view

[fde31]

Currently the patcher management happens as part of the graph editor in a drawer, which also adds to the complexity of differentiating between patchers and nodes in the graph that have been instantiated from a patcher.

Moving patcher management to a top level view accessible via the main nav can allow for enhanced export management in the future (renaming, deleting etc) but also isolate things like "Default Preset to load upon Node instantiation" in a dedicated view rather than doing it in the instance and graph view where the user might have slightly different assumptions given the context.