Continue adding support for user created subgraphs

[adamgerhant]

Closes #2043
Allows removing, renaming, and reordering imports/exports.
Input based properties for network nodes to allow useable reordering
Adds Tooltips for acceptable types of a node input
Annotations for both node and input based overrides added to the node macro

Reworks how the properties panel is generated. A full node level override for the entire panel is still possible, which is stored as a lambda in the definition. Modifying the imports/exports means that the reference is lost, and the properties are instead generated individually for each input. By default, this will use the data type/type annotation to generate an appropriate set of widgets. This is done in property_from_type. For custom input overrides, each input has the PropertiesRow struct, which can store a reference to a widget override (a lambda which will generate a custom set of widgets). This lambda is stored in a hashmap, since it would not be possible to serialize it for every node. This also makes it easily extendible, just like how the definitions are stored. This lambda has access to the entire network interface, which it can use to access any information it needs to generate the widget. In addition to the widget override reference, each input also stores a hashmap of serializable data, which can store any information necessary. For the most part this will just contain the input name, but the author of the node could store additional data as they need.

TODO:

• Rename inputs in properties panel (deferred)
• Automatic Into node insertion with drop down menu (deferred)
• Protonode name at top of properties panel
• Hiding input should automatically disconnect
• Filtering out the primary inputs of autogenerated Properties panel node sections so only secondary inputs are shown (e.g. Ellipse and Merge nodes)
• Valid input types for the identity node crashes
• Upgrading previous documents

[Keavon]

Deferred code review comments/requests from Hypercube in the precursor PR to this one:

• Add merging nodes into a subgraph with Ctrl+M and basic subgraph signature customization #2097 (comment)
• Add merging nodes into a subgraph with Ctrl+M and basic subgraph signature customization #2097 (comment)
• Add merging nodes into a subgraph with Ctrl+M and basic subgraph signature customization #2097 (comment)