fix: default editor focus setting failure

[LIlGG]

What type of PR is this?

/kind bug
/area editor
/area ui

What this PR does / why we need it:

当前为默认编辑器设置焦点的时机放在 onMounted 时，但此时默认编辑器可能还未加载成功且标题也为能成功加载，因此无法保证正确设置标题焦点。

当前 PR 将此时机放置在默认编辑器创建完成之后的 onCreate ，此时将能够保证焦点设置成功。

How to test it?

测试默认编辑器能否正常设置标题或内容的焦点。

Which issue(s) this PR fixes:

Fixes #6060

Does this PR introduce a user-facing change?

解决使用默认编辑器时无法正确设置焦点的问题

[LIlGG]

/milestone 2.17.x

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.1% Duplication on New Code

See analysis details on SonarCloud

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 56.44%. Comparing base (5fdf6c0) to head (d78cbce).
Report is 233 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #6062      +/-   ##
============================================
- Coverage     56.91%   56.44%   -0.47%     
- Complexity     3319     3538     +219     
============================================
  Files           587      623      +36     
  Lines         18968    20950    +1982     
  Branches       1401     1478      +77     
============================================
+ Hits          10795    11825    +1030     
- Misses         7594     8525     +931     
- Partials        579      600      +21     

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[guqing]

/lgtm

[ruibaby]

/lgtm

[f2c-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ruibaby

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• ui/OWNERS [ruibaby]

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