Adds multi-row insert with list of dictionaries (#663)

[lilacse]

I ended up figuring it out myself :) seems like this is the only way to catch most of (if not all, since, we never know...) the possible input errors regardless of the implementation passed to the argument.

It reuses the current overload for insert multi records (the new overload simply calls it after converting the argument into a list of columns and a list of values), so there are not a lot of changes overall.