feat: add IsNotBlank decorator and corresponding tests

[gabriel-logan]

Description

Checklist

• the pull request title describes what this PR does (not a vague title like Update index.md)
• the pull request targets the default branch of the repository (develop)
• the code follows the established code style of the repository
  • npm run prettier:check passes
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• tests are added for the changes I made (if any source code was modified)
• documentation added or updated
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Fixes

fixes #[issue number], fixes #[issue number]

#543

IsNotBlank is a very important decorator and the lack of it is a big hindrance. I know it's easy to implement, but having it directly natively in the lib will certainly make things easier and please other devs.

[braaar]

There are so many permutations of this concept that I think we're better off just using #1579 for this type of stuff

[github-actions]

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