As a Lexeme creator I want to be able to specify the Lexical category of my Lexeme from all other possible Items in order to define the lexical category of my new Lexeme.

Problem:
We need a way to allow editors to specify the lexical category of the Lexeme they are creating.

Screenshots/mockups:
https://www.figma.com/file/XoYktoKEBnC0VIf1SRuxJK/Lexicographical-Data-UI?node-id=493%3A3077

BDD
GIVEN the special page to create a new Lexeme
THEN I can specify the lexical category of the new Lexeme using an Item lookup

Acceptance criteria:

• special page has lexical category lookup
• lookup selects from all Items on the Wikibase instance

Notes:

• This is the same as for language lookup but with lexical category instead.
• Component: Wikit lookup component
• Placeholder text: The Lexeme’s category, e.g., ‘numeral’