As a template editor I want to be able to access the Lemma(s) of a Lexeme in order to show a meaningful representation instead of just an ID to the user.
In order to be able to reference a Lexeme in wiki text and show its Lemma we should have a Lua function that takes a Lexeme ID and returns the Lemma of that Lexeme.
**Example:**
for example `mw.wikibase.getLemmas( lexemeId )` would return a table (indexed by language codes) holding tables consisting of the language + the lemma (like in the JSON representation). Like `de => { language => 'de', value => 'Haus' }`.
See also https://www.mediawiki.org/wiki/Extension:Wikibase_Client/Lua
**BDD**
GIVEN
AND
WHEN
AND
THEN
AND
**Acceptance criteria:**
*
**Open questions:**
* How do we want to track these data usages? We will initially start with tracking them as other usages, and potentially create a more specific usage type later on (or track them as label usages once WikibaseClient is ready for that).
* Can we do the same for Forms/Senses? Yes: `mw.wikibase.getGlosses( senseId )`/`mw.wikibase.getReprensetations( formId )`
* What do we return if there are multiple Lemmas? Should they just be concatenated or should they hint which spelling variant they have? We will return everything (equivalent to [[https://www.wikidata.org/wiki/Special:EntityData/L1.json|JSON format]])
* Do you want to be able to select a specific spelling variant's Lemma with another function? For now, no.
* Currently Lua is disabled for access to Lexeme data. How did we do this? Can we re-enable it just bit-by-bit? Yes, this is independent from getting whole entities.