bug(mac): migration should occur before installation completion check

[sgschantz]

Describe the bug

When running Keyman Configuration after installing a new version of Keyman, if data migration is needed it should happen immediately. This way, the configuration window will update with the migrated data promptly instead of waiting until the user has clicked the first button in the installation window.

Keyman apps

• Keyman for Android
• Keyman for iPhone and iPad
• Keyman for Linux
• Keyman for macOS
• Keyman for Windows
• Keyman Developer
• KeymanWeb
• Other - give details at bottom of form

Keyman version

alpha 19