fix: adjust the initial array size of fs

fix(sync) if FpEqMsg return error, do not enqueue msg

fix: error in schemaless with same timestamp

refactor: mnode worker

feat(stream): partition by

enh(query): add first/last function distributed implementation

docs: refine keywords section and add delete keywords

test: add test case for tail , notice that this case only support sub table  and common table

fix(sync): send snapshot to multi nodes at the same time

fix: handle the memory leak of parser