feature: support ipv6

[Ifdevil]

• I have registered the PR changes.

Ⅰ. Describe what this PR did

改造目标：使seata支持ipv6，增加server端和client端对ipv6地址校验及解析；

改造思路：seata使用的第三方库本身也对IPv6有支持,所以本次Seata对IPv6的支持改造主要是对IP地址的解析和校验.
1、对NetUtil工具类改造，增加ipv6校验和解析
2、discovery模块，修改服务发现解析ip:port的代码
3、ChannelManager#readClientId方法修改

Ⅱ. Does this pull request fix one issue?

fixes #5846
fixes #5607

Ⅲ. Why don't you add test cases (unit test/integration test)?

代码正确的话，补充缺少的测试单例和注释

Ⅳ. Describe how to verify it

将当前代码部署到ipv4和ipv6环境下，对各个事务模式进行业务案例测试，确保在ipv6及ipv4环境下，可以正常通信及事务功能

Ⅴ. Special notes for reviews

NetUtil#toLong方法没有看到调用，不确定是否需要修改，如需修改，请给点建议吧
有其他问题，我会及时修改的

[CLAassistant]

All committers have signed the CLA.

[codecov]

Codecov Report

Merging #5902 (2c8a525) into 2.x (5c28eeb) will decrease coverage by 0.08%.
Report is 1 commits behind head on 2.x.
The diff coverage is 51.00%.

❗ Current head 2c8a525 differs from pull request most recent head 4ce4a4e. Consider uploading reports for the commit 4ce4a4e to get more accurate results

Additional details and impacted files

@@             Coverage Diff              @@
##                2.x    #5902      +/-   ##
============================================
- Coverage     48.76%   48.69%   -0.08%     
- Complexity     4434     4445      +11     
============================================
  Files           819      820       +1     
  Lines         28610    28695      +85     
  Branches       3569     3591      +22     
============================================
+ Hits          13951    13972      +21     
- Misses        13197    13254      +57     
- Partials       1462     1469       +7     

Files	Coverage Δ
...very/registry/zk/ZookeeperRegisterServiceImpl.java	61.31% <100.00%> (ø)
...eata/core/rpc/netty/NettyClientChannelManager.java	61.31% <0.00%> (ø)
...ta/discovery/registry/FileRegistryServiceImpl.java	0.00% <0.00%> (ø)
...covery/registry/etcd3/EtcdRegistryServiceImpl.java	11.36% <0.00%> (ø)
...n/java/io/seata/core/rpc/netty/ChannelManager.java	0.00% <0.00%> (ø)
.../io/seata/common/util/NetAddressValidatorUtil.java	65.71% <65.71%> (ø)
...on/src/main/java/io/seata/common/util/NetUtil.java	53.48% <50.94%> (-3.49%)	⬇️

... and 6 files with indirect coverage changes

[slievrly]

LGTM
Pls. Add change to the following file:
https://github.com/seata/seata/blob/2.x/changes/en-us/2.0.0.md
https://github.com/seata/seata/blob/2.x/changes/zh-cn/2.0.0.md