[Feature][DerivedData] Add an environment variable to customize the derived data path

[PatShen]

I made this PR to add an environment variable COCOAPODS_DERIVED_DATA_PATH to customize the -derivedDataPath of xcodebuild when user attempts to run the CocoaPods command, such as pod lib lint, pod repo push, etc.

[PatShen]

When I set the environment variable like COCOAPODS_DERIVED_DATA_PATH=~/Desktop/DerivedData, the script will run with a -derivedDataPath parameter