AO3-7505 Fixing the error messages for blank collection names and titles and i18n-ing collection.rb

[ASalbenblatt]

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Issue

https://otwarchive.atlassian.net/browse/AO3-7505

Purpose

The errors for blank collection titles and names used to say:

• Name Please enter a name for your collection.
• Title Please enter a title to be displayed for your collection.
  This fix corrects them so they say:
• Please enter a name for your collection.
• Please enter a title to be displayed for your collection.

I also i18n-ed the file I was working in which was app/models/collection.rb

Testing Instructions

In addition to the testing listed in Jira, all text should be in t() functions, and it should all display properly and identically to how it did before throughout the collection creation screen.

Credit

FlyingFalcon they/them

[ASalbenblatt]

I know it looks like rubocop is still failing, but that's just because the migration hasn't been schema dumped, and rubocop only looks at the schema file (docs on this)