Enable placement on more `scalar_fn`s to allow lowering and pushdown to `TableScan`s

[joseph-isaacs]

We should use the new placement API for more scalar fns. This allows better query plans for example in vortex we get a large speed up for clickbench query q29 (below) when pushing down OCTET_LENGTH("URL") since we never need load the URL str bytes

SELECT "CounterID", AVG(OCTET_LENGTH("URL")) AS l, COUNT(*) AS c FROM hits WHERE "URL" <> '' GROUP BY "CounterID" HAVING COUNT(*) > 100000 ORDER BY l DESC LIMIT 25; -- ClickHouse's length counts bytes, not code points as standard SQL.

Scalar fn:

• bit/octet/''-length
• todo

Please add any more and we can update the list