Feat add accepted mime types in import action

[fadilAndrian]

fix(ImportAction.php): add support for custom acceptedMimeTypes in the FileUpload component to allow for more flexible file type validation

Proposed changes

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• ✨ New feature (non-breaking change which adds functionality)
• 🛠️ Bug fix (non-breaking change which fixes an issue)
• ❌ Breaking change (fix or feature that would cause existing functionality to change)
• 🧹 Code refactor
• ✅ Build configuration change
• 📝 Documentation
• 🗑️ Chore

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[tiagof]

Hi.
First of all let me say i'm not the owner not a maintainer of this project, nevertheless here are my 2 cents:

• don't add any IDE specific files to the repo. In this case, remove .idea/
• keep the project's code style. If it uses null | Closure, don't go replacing it with ?Closure. - I know this is (pobably) automatically done by your IDE...don't let it.
• same goes for reordering use (traits), although not so "critical"
• make sure you add tests for every added feature.

Finally, thanks for this PR, hope the feature get's added since I'll have use for it :)