feat(tianmu) Improve the performance of master slave synchronization and the performance of the execution interface for modifying data(889)
1.
When synchronizing data, push down the conditions for delete and update.
Only qualified data will be scanned to avoid full table scanning.
When executing the push down condition, tianmu will use metadata to perform rough filtering to determine the qualified packages.
In addition, when executing the push down condition, we only need to make a materialization comparison on the qualified records,
instead of making a materialization comparison on the unqualified records.
2.
Improve the execution speed of (delete_row) and (update_row) functions. At present, it is considered to parallelize the modification of each column

[summary]
1. "log/tianmu.log" --> "tianmu_engine.log"
2. "trace.log" --> "tianmu_trace.log"
3. "query.log" --> "tianmu_query.log"

[summary]

NULL-->nullptr
namespace "DBHandler"-->"handler"
class TianmuHandler-->ha_tianmu
sdb-->tianmu
functions in ha_my_tianmu.cpp all renamed with prefix "ha_my_tianmu_xxx"

class member variable refactor：handler directory

[summary]
1 change tianmu status var scope from SHOW_SCOPE_UNDEF to SHOW_SCOPE_GLOBAL;

[summary]
1 innodb(in 5.7) system variable "innodb_large_prefix" default value is ON, follow it;

(1). implement tianmu's virtual function max_supported_key_part_length;
(2). enlarge max_supported_key_length's return value from 1024 to 16*1024;
Co-authored-by: Nmergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

Co-authored-by: Nmergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

This is a series of #11, which is used to improve the tianmu code quality.
Co-authored-by: Nmergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

[summary]
1. Change all engine stonedb to tianmu
2. Change SDB to tianmu
3. Also include mysql-test
4. Change file magic number to TianmuTB

Co-authored-by: zhx <zhx>