text: Title: Spaces are not normalized when matching keywords with embedded arguments
  Body: When matching normal keywords, different kind of spaces are considered equal. For example, using a keyword so that there's the no-break space instead of the normal ASCII space in its name is fine. No-break spaces have been normalized for ages (#1264) and I believe we started to normalize all spaces when the new parser was taken into use in RF 3.2.
  
  This kind of normalization isn't done, however, with keywords containing embedded arguments. In practice this means that using a keyword like `Given a good example` so that one of the spaces is a no-break space, or some other Unicode space, fails. A related problem is that the emitted error is `No keyword with name 'Given a good example' found.` and it's hard to understand why there's no match when the name looks just fine.
  
  This is relatively easy to fix, but different spaces need to be taken into account both in the keyword name itself and in the possible BDD prefix. I actually noticed this issue when investigating ways to make matching BDD prefixes faster after PR #5096 changed keyword matching logic so that BDD style keywords are matched first.
  
  Although we can normalize spaces pretty easily, we cannot make keywords with embedded arguments space-insensitive similarly as normal keywords are. I believe that's fine.