Adjust path tracing of sharding-opentracing

[tuohai666]

• Add tracing of getConnection().
• Add tracing of close().
• Add tracing of parse().
• Remove tracing of route().
• Remove tracing of merge().
• Display correctly without a WebServer.
• Display jdbc url in peer tag.
• Vertical dimension sort by time between threads: Vertical dimension sort by time between threads skywalking#1657
• Update component name: Update component name since ShardingJDBC has changed its name to Sharding-Sphere skywalking#1658
• Support Sharding-Proxy.
• Change the event mechanism to invoke-chain.
• Rename OverallExecutionEvent and move to a appropriate place.
• Make feature optional for Proxy by configuration.
• Aggregation for sub-threads. (Need to implement in plugin.)
• Use SPI to instead of guava event bus for performance issue

[tuohai666]

Topology

Tracing

Detail

[tuohai666]

Display jdbc url in peer tag.

[terrymanu]

Guava event bus's performance is really low, I just call directly instead of event bus, the performance is fast 50%.
So I just use SPI to decouple, do not use event bus on online query.

Use guava event bus:

Guava event bus (nanos)	SPI (nanos)	Get connection(Hikari) (nanos)
814489	63190	345827

event bus is slow than get connection!

[terrymanu]

full time spend for get 2 connection and post a event:

use guava event bus:
post evert--------: ds_0---814489
get connection---: ds_0---452882
get connection---: ds_0---345827
total-------------: ds_0---2847346

post evert-----------: ds_1---792603
get connection------: ds_1---459552
get connection------: ds_1---303029
total---------------- :ds_1---2819832

use SPI:
post evert-----------: ds_0---63190
get connection------:ds_0---618804
get connection------:ds_0---469503
total----------------:ds_0---1326277

post evert-----------:ds_1---69040
get connection------:ds_1---574488
get connection------:ds_1---562666
total-----------------:ds_1---1349838