Merge pull request #113 from binbin0325/nacos_2.x

upgrade nacos v2.x

update nacos v1 (#109)

fix slices length bug in AcquireBytes from bug from pr #108

update nacos version to 2.1.2 (#106)

* support for nacos v2.1.0

* mv nacos/v2 nacos

* fix format

* set nacos-sdk-go to 2.1.2 and client close func

* update nacos port

* client close and client set nil

* fix data race

* update test to assert

* fix import

Co-authored-by: bobtthp <bobtthp@bob-Mac-mini.local>
Co-authored-by: bob <bob@bobdeMacBook-Pro.local>

change big decimal interface

move part of dubbogo common module to gost

check connection aliveness

add check connection aliveness

change conncheck.go license header format

check connection aliveness