Similar to the recent work for commands, track and expose the creating
plugin for convars. The first plugin to register a given cvar becomes
the owner until that plugin is unloaded. If a plugin attempts to
register a convar that was already registered and the originally
registering plugin has been unloaded, that plugin becomes the owner.
This isn't quite as nice as the way commands shift "ownership" as
plugins are unloaded, but we don't have a sane data structure currently
to implement that, and it seemed like a lot of unnecessary work as there
shouldn't really be multiple plugins with conflicting cvars.
Closes#1492
* Execute ConVarQueryFinished if client disconnects
So people passing handles to the extra data can close them, adds a new return value to check if this happened
* Update based on suggestion
Co-authored-by: Asher Baker <asherkin@limetech.io>
* Update based on notes
* Normalize
* Pass along cookie handle instead of invalid
Co-authored-by: Asher Baker <asherkin@limetech.io>
