little bit of code reformatting

[ccreutzi]

• Removed a few extra parentheses on if conditions
• Replaced custom setters with property validations – after verifying that just removing the custom setters does trigger test failures
• Reformatted acceptable model names so that the lines are logical groups – should make future diffs a tiny bit easier to read

[vpapanasta]

Or if ~isempty(systemPrompt )

[ccreutzi]

Keeps being tempting, but it's not the same thing. Strings are “proper” matrices, and a scalar can't be empty.

>> isempty("")

ans =

  logical

   0