[Language] Adds rule for lonely quoted text

[jpelay]

Description

Adds a new exception in level 4 to detect lonely quoted text. Like this:

Fixes #3375

How to test

I added a small test for this behavior.

Checklist Done? Check if you have it all in place using this list:*

• [x] Describes changes in the format above (present tense)
• [x] Links to an existing issue or discussion
• [x] Has a "How to test" section

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