Package Management

[ethanashaw]

Major changes

• Refactor package installation form and related components to follow new design

Minor changes

• Add VITE_SELECT_ALL_INSTANCES_ENABLED environment variable. It controls the "Select all instances on all pages" feature. Right now, it will be disabled by default because it's unsupported by some instance actions on the backend.
• Convert boldSubstring helper to a component, BoldSubstring, to avoid duplication across helpers
• Add ref prop to LoadingState to allow it to be used as an intersection observer target in infinite scrolling scenarios
• Replace "Upgrade instances" button with new "Manage packages" actions in the instances page
• Update mock packages handler to enable exact search
• Add pluralizeWithCount helper for the common use case of having a number immediately followed by a pluralized word