Co-Authored-By: NAlexander Kuzmenkov <36882414+akuzm@users.noreply.github.com>

refactoring: extract ArrayJoinAction class

Sometimes it is useful to know how much does this data will take on
disk, with blockSerializedSize() you can know this (although without
compression).

This can be a major knowledge for various aggregation functions that
tracking some state (i.e. uniqCombined).

Use the generic class ext::scope_guard for subscriptions in IAccessStorage instead of a special class.

Accept String or FixedString data types as key for maps in the
SummingMergeTree now that sumMap supports these two types (introduced in
bc0fbd68).
Signed-off-by: NBaudouin Giard <bgiard@bloomberg.net>