Add SKIP and LIMIT to the QueryGraph
Make Ronja plan SKIP and LIMIT together with ORDER BY
Add Cost and Cardinality for SORT, SKIP and LIMIT
Add new pipes

o Add LimitPipe, SkipPipe and a new SortPipe
o Rename the old SortPipe to LegacySortPipe
Let projection be done before sorting

When sorting, a row needs to be compared with other
rows quickly and multiple times. To facilitate this,
force projection to happen, so sorting doesn't have
to execute an expression for every comparison.
Merge pull request #2324 from systay/ronja-slice

SKIP and LIMIT for Ronja