cherry-pick: ユーザーコンテンツのインポート操作の実行可否をロールで制御できるように

[adzukimame]

What

• enhance: ユーザーコンテンツのインポート操作の実行可否をロールで制御できるように (# 14583)

Why

Additional info (optional)

[codecov]

Codecov Report

Attention: Patch coverage is 23.68421% with 145 lines in your changes missing coverage. Please review.

Project coverage is 42.16%. Comparing base (e911f3f) to head (254cfab).
Report is 1 commits behind head on develop-mame.

Files with missing lines	Patch %	Lines
packages/frontend/src/pages/admin/roles.editor.vue	0.00%	100 Missing ⚠️
packages/frontend/src/pages/admin/roles.vue	0.00%	40 Missing ⚠️
...ages/frontend/src/pages/settings/import-export.vue	0.00%	5 Missing ⚠️

Additional details and impacted files

@@                Coverage Diff                @@
##           develop-mame     #174       +/-   ##
=================================================
+ Coverage         20.62%   42.16%   +21.53%     
=================================================
  Files               709     1516      +807     
  Lines             94892   189357    +94465     
  Branches           1030     3559     +2529     
=================================================
+ Hits              19576    79843    +60267     
- Misses            74787   108967    +34180     
- Partials            529      547       +18     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.