feat: add an API to invalidate theme template cache

[guqing]

What type of PR is this?

/kind feature
/area core
/area theme
/milestone 2.16.x

What this PR does / why we need it:

为主题管理增加在线清理缓存功能

Which issue(s) this PR fixes:

Fixes #5440

Does this PR introduce a user-facing change?

为主题管理增加清理模板引擎缓存的功能。

[guqing]

@ruibaby 帮忙在 Console 主题管理增加一个清理缓存按钮

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.2% Duplication on New Code

See analysis details on SonarCloud

[codecov]

Codecov Report

Attention: Patch coverage is 73.33333% with 4 lines in your changes are missing coverage. Please review.

Project coverage is 56.52%. Comparing base (5fdf6c0) to head (fb0b506).
Report is 169 commits behind head on main.

Files	Patch %	Lines
...n/halo/app/core/extension/theme/ThemeEndpoint.java	73.33%	4 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #5906      +/-   ##
============================================
- Coverage     56.91%   56.52%   -0.39%     
- Complexity     3319     3463     +144     
============================================
  Files           587      612      +25     
  Lines         18968    20488    +1520     
  Branches       1401     1413      +12     
============================================
+ Hits          10795    11581     +786     
- Misses         7594     8326     +732     
- Partials        579      581       +2     

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[ruibaby]

/lgtm

[JohnNiang]

/approve

[f2c-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: JohnNiang

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