shouldMigrate can cache its result based on a hash of the package.json content.

[KristianDD]

Is your feature request related to a problem? Please describe.

shouldMigrate is executed on many commands and has a performance impact on their execution.

Describe the solution you'd like

The result of the shouldMigrate method can be cached based on the package.json content.

Describe alternatives you've considered

None

Additional context

Acceptance Criteria
Should use patch version of CLI 6.2.x
1 First tns migrate --log trace should log
Executed shouldMigrate for platforms: Android,iOS. Result is: undefined
2 Second execution should log:
Got cached result for shouldMigrate for platform: Android
Got cached result for shouldMigrate for platform: iOS
3 Change in package.json and then tns migrate --log trace should log
Executed shouldMigrate for platforms: Android,iOS. Result is: undefined