chore: replace utf8 migration charset to utf8mb4

[chengjoey]

What this PR does / why we need it:

replace utf8 migration charset to utf8mb4

Which issue(s) this PR fixes:

• Fixes #your-issue_number
• Erda Cloud Issue Link

Specified Reviewers:

/assign @luobily

ChangeLog

Language	Changelog
🇺🇸 English	replace utf8 migration charset to utf8mb4
🇨🇳 中文	将所有migration的默认charset改为utf8mb4

Need cherry-pick to release versions?

Add comment like /cherry-pick release/1.0 when this PR is merged.

For details on the cherry pick process, see the cherry pick requests section under CONTRIBUTING.md.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (827fa3a) 22.62% compared to head (a974015) 22.68%.
Report is 7 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6251      +/-   ##
==========================================
+ Coverage   22.62%   22.68%   +0.06%     
==========================================
  Files        1831     1833       +2     
  Lines      195972   196278     +306     
==========================================
+ Hits        44334    44523     +189     
- Misses     146571   146639      +68     
- Partials     5067     5116      +49     

see 17 files with indirect coverage changes

[sfwn]

failed to run db migration check: you can not modify files after applied.

I think you should write patch SQLs to adjust charsets.