In the Explore tab, the system filter is not working properly.

Several issues should be fixed:

• OwlPlug registry only provides mac as targets, but expected values could be mac-x64 or mac-arm64
• Filters for mac-x64 or mac-arm64 are missing
• Query specifications for targets are chained with and() clause, but it should be processed in a single and(list) as done with formats.
• By default, only compatible targets are displayed in the UI. The checkboxes could be initially checked with the current system configuration.
• System target should be clearer in the package UI