Treat suggestion lines the same as code lines

What does this MR do?

This fixes the issue where copying code from a suggestion would erroneously copy line numbers and add in extra new lines.

Example - when copying the new content in the following suggestion

Before:

# Other files and folders testing change
    
   
    8
   new line
    
   
    9
   second new line
    
   
    10
   
    
   
    11
      Indented line

After:

# Other files and folders testing change
new line
second new line

   Indented line

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team