feat: make a category required for new items

[donni106]

• added check for nested values when converting params to avoid creation of empty ones
• made at least one category input visible on load for news items
• added flashs and redirect + return for create and edit actions if no category selected

SVA-281

[codeclimate[bot]]

Code Climate has analyzed commit 24b9248d and detected 1 issue on this pull request.

Here's the issue category breakdown:

Category	Count
Security	1

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