- extension manager has been made responsible for extension update directory information
- extension manager has been enhanced to ensure that previously left extension update metadata is deleted before installing an extension
- extension manager has been enhanced to ensure that extension update metadata is deleted when extension is being removed
- refactored extension command tests for manager change, ensuring previous and expected states along with returned release info
- refactored extension manager tests for ensuring previous extension update entries are removed before installing extension
- created extension manager test for installing local extension
- centralized logic for checking and ensuring extension name is "gh-" prefixed