remove FullWeighting and Injection legacy level transitioners
level transition: some tweaks and fixes for SpaceInvariantTimeTransitioner
tests: for SpaceInvariantTimeTransitioner
tests: minor fix for Scalar1D data structure
MultiLevelProvider: adjustments to support AbstractLevel and AbstractLevelTransitioner
tests: MultiLevelProvider now 100% coverage
deleting not required MultiLevelProvider specialization for time levels

note: modules/classes importing this have not been fixed/adjusted/edited