As an editor I want to have the merging of certain Lexemes blocked in order to avoid mistake merges that take unnecessary time to revert and untangle.
**Screenshots:**
Error when trying to merge two items with different descriptions for the same language:
{F22636013}
**BDD**
GIVEN I want to merge two Lexemes
AND they link to each other in any statement (doesn't matter if on the Lexeme, Form or Sense level)
THEN the merge is not done
AND I get an error message saying "Failed to merge Lexemes, please resolve any conflicts first. Error: Lexemes link to each other in a statement."
GIVEN I want to merge two Lexemes
AND they have different Lemmas in the same spelling variant
THEN the merge is not done
AND I get an error message saying "Failed to merge Lexemes, please resolve any conflicts first. Error: Lexemes have different Lemmas for the same spelling variant."
GIVEN I want to merge two Lexemes
AND they have different language and/or lexical category
THEN the merge is not done
AND I get an error message saying "Failed to merge Lexemes, please resolve any conflicts first. Error: Lexemes have different language and/or lexical category."
GIVEN I want to merge two Lexemes
AND I enter the same Lexeme id twice
THEN the merge is not done
AND I get an error message saying "Failed to merge Lexemes. Error: The provided Lexeme IDs are identical."
**Acceptance criteria:**
* All of the above cases result in an aborted merge.
** the merge fails on the first problem, showing the respective message