1. replace all boost::shared_ptr to std::shared_ptr
2. replace all boost::scopted_ptr to std::unique_ptr
3. replace all boost::scoped_array to std::unique<T[]>
4. replace all boost:thread to std::thread
1. Fix bug of UNKNOWN Operation Type 91
2. Support using resource_tag property of user to limit the usage of BE
3. Add new FE config `disable_tablet_scheduler` to disable tablet scheduler.
4. Add documents for resource tag.
5. Modify the default value of FE config `default_db_data_quota_bytes` to 1PB.
6. Add a new BE config `disable_compaction_trace_log` to disable the trace log of compaction time cost.
7. Modify the default value of BE config `remote_storage_read_buffer_mb` to 16MB
8. Fix `show backends` results error
9. Add new BE config `external_table_connect_timeout_sec` to set the timeout when connecting to odbc and mysql table.
10. Modify issue template to enable blank issue, for release note or other specific usage.
11. Fix a bug in alpha_row_set split_range() function.
At present, the application of vlog in the code is quite confusing.
It is inherited from impala VLOG_XX format, and there is also VLOG(number) format.
VLOG(number) format does not have a unified specification, so this pr standardizes the use of VLOG
1. Support limit clause push down both odbc table and mysql table.
2. Code refactor of ODBC Scan Node, change `build_connect_string` and `query_string` from BE to FE to make it easily to modify
