As an admin I want banned editors not to be able to create new Lexemes.

Problem:
We need to ensure that permissions are checked before creating a new Lexeme.

BDD
GIVEN an editor who is blocked from creating new Lexemes
OR the Lexeme namespace being locked from new Lexeme creation
WHEN attempting to create a new Lexeme
THEN the attempt is blocked
AND the new Lexeme is not created

Acceptance criteria:

• permissions of the editor and namespace are checked before a new Lexeme is created

Notes:

• We need to ensure that the existing permission checks are carried over. The existing permission error messages can be taken over.