LPS-48330 Add new helper method to collect selected layouts in json format
LPS-48330 "layoutIds" hidden field won't contain checked pages correctly when pages tree doesn't load all selected nodes at first time
LPS-48330 Source formatting
LPS-48330 Add tests
LPS-48330 Small SF - more descriptive var name
LPS-48330 Adding explanation comment
LPS-48330 SF
LPS-48330 SF
LPS-48330 SF