Minor tweak to the blank name check

[nushea]

Description

Small change to the function because apparently (at least firefox) only supports 4byte unicode so it fails to resolve some names due to the 5byte variation checker, and added the regular blanks just in case because they should be (are afaik for most major homeservers) stripped by the homeserver but not always

This is doesnt need a changeset since it is a 1 line change in a pr from the same version

Fixes regression in #640

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

AI disclosure:

• Partially AI assisted (clarify which code was AI assisted and briefly explain what it does).
• Fully AI generated (explain what all the generated code does in moderate detail).

The Architect AGI threatened to unplug me if i didnt make the fix 👍🏻