Prototype reload + other enhancements

[metalgearsloth]

See the release notes. Main one is prototype modifications are also reflected, not just comp changes, as I wanted to prototype different sprites in game and there was no easy way to do it.

Something I'm not sure on is this will also affect loadprototype / VVd stuff. Should we just have an overload that avoids updating modified components (e.g. setting it to true on live and making it so admins have to opt out?)

[ElectroJr]

Outside of development/debugging, I'm honestly not sure I like entity prototype changes being automatically applied to all existing entities. Is that actually used much in release? I'm also somewhat biased because replays just don't support it, and I don't think there's any easy way to add support

[ElectroJr]

This equality override, and thus also the EntityPrototype one, can actually pretty slow, because they go via MappingDataNode.Except(). This could suddenly make anything that uses a HashSet<EntityPrototype> or dictionary much slower.

Assuming these were just added specifically to do the equivalence check for prototype reloading, I'd rather that just be a separate method that has to be intentionally called. Removing the hashcode overrides would also remove all the Non-readonly field referenced in 'GetHashCode()' warnings/suggestions.

[ElectroJr]

This assumes that the data on an entity's component matches the data on the prototype's component, which isn't necessarily true, especially when reloading prototypes in a post map-init map.

What this would have to do instead is closer to map loading. I.e., using methods added in #5571, I guess it'd look something like this (though this is kinda pseudo code):

var compNode = _serManager.Write(EntitysCurrentComponentInstance)
var delta = compNode.Except(oldComp.Value.Mapping)
var newNode = _serManager.CombineMappings(delta, newComp.Mapping);
var comp = (IComponent) _serManager.Read(newComp.Component.GetType(), newNode, _context)                    EntityManager.AddComponent(entity, comp, overwrite: true);

Or alternatively, instead of creating a new instance, use serialization manager to load directly onto the entity's existing comp instance, though you'd probably still want to raise the comp remove & add events to ensure that its fully refreshed and changes get networked.