fixes #12623 - Add extra parameter to the ScheduledFargateTaskProps to allow PlatformVersion to be passed. Rearranged code to handle EC2 & Fargate lanuch types correctly

Add a new test to cover the changes in the previous commit. Tests whether the Rule Target has a defined platform version (1.4.0) rather than the default LATEST

Rearrange the imports into the correct order

Add a new section to the readme to explain the platform version option

Change double quotes to single quotes

Revert the code to remove the function breaking change. EC2 Task uses old functions and the Fargate Task builds the ECS Task and then adds it to the target separately

fix some PR issues and add a comment and remove the ecstask import