Pass game instance from cmdline to GUI/ConsoleUI

[HebaruSan]

Problem

If you have multiple game instances, you can choose between them with these command line options:

  --ksp                   KSP install to use

  --kspdir                KSP dir to use

However, these currently don't work for GUI or ConsoleUI. Instead, they will use the default instance if one is defined, or ask the user to choose an instance.

For GUI, these options are allowed and parsed (to the extent of raising an error if an invalid instance is specified), but not used to drive the UI.

For ConsoleUI, these options are not considered valid.

Changes

Now the --ksp and --kspdir flags work for both GUI and ConsoleUI.

The knowledge of which instance to use is stored into CmdLine's KSPManager object by InstanceSpecificOptions.Handle. To make GUI and ConsoleUI obey this, we pass this same manager object to them via new parameters.

Fixes https://forum.kerbalspaceprogram.com/index.php?/topic/154922-ckan-the-comprehensive-kerbal-archive-network-v1251-broglio/&do=findComment&comment=3380669