refactor: add warning alert for H2 database on data initialization page

[ruibaby]

What type of PR is this?

/area ui
/kind improvement
/milestone 2.19.0

What this PR does / why we need it:

将 H2 数据库使用警告放置在数据初始化页面，之前放在初始化表单页面无法正确判断，因为没有登录，无法调用 /actuator/info 接口获取数据库数据。

Fixes #6561

Special notes for your reviewer:

需要使用此 PR 测试使用 H2 数据库全新安装，观察是否在数据初始化页面有 H2 数据库的使用提示。

Does this PR introduce a user-facing change?

None

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 58.03%. Comparing base (6cd8dc8) to head (0c703de).
Report is 44 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #6564      +/-   ##
============================================
- Coverage     58.18%   58.03%   -0.15%     
- Complexity     3774     3915     +141     
============================================
  Files           651      670      +19     
  Lines         22125    22954     +829     
  Branches       1538     1573      +35     
============================================
+ Hits          12873    13322     +449     
- Misses         8641     9015     +374     
- Partials        611      617       +6     

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[JohnNiang]

/lgtm

[f2c-ci-robot]

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This pull-request has been approved by: JohnNiang

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