.*: add compactor for syncer

[GMHDBJD]

What problem does this PR solve?

add compactor to compact dml

What is changed and how it works?

# Assuming that UPDATE statement does not update the primary key. If no primary key, choose a UNIQUE NOT NULL Key.
# If UPDATE statement update the primary key or unique key, split it into one DELETE and one INSERT statement.
# We list two successive DMLs of one row and the result that can be compacted. X means this situation will not happen.
INSERT + INSERT => X
INSERT + UPDATE => INSERT
INSERT + DELETE => DELETE
UPDATE + INSERT => X
UPDATE + UPDATE => UPDATE
UPDATE + DELETE => DELETE
DELETE + INSERT => UPDATE
DELETE + UPDATE => X
DELETE + DELETE => X

Check List

Tests

• Integration test
• UT