Revert "enh(tsdb): data migrate should not block data r/w and commit"

refactor(query): do some internal refactor.

Update 13-schemaless.md

Update 03-opentsdb-telnet.mdx

Update 04-opentsdb-json.mdx

Update 03-opentsdb-telnet.mdx

Update 02-influxdb-line.mdx

Update 04-opentsdb-json.mdx

Update 02-influxdb-line.mdx

Update 13-schemaless.md

feat(query): interp support return timestamp with pseudo column _irowts 

docs: improve the system table chapter

enh(tsdb): data migrate should not block data r/w and commit

fix: memory leak