We want to make statements on Lexemes that reference Senses on other Lexemes.
Example usage: on the Lexeme "hard"/Sense "resisting deofrmation" we'd have a statement "antonym: easy to deform". "easy to deform" would be a sense on the "soft" Lexeme.
For the baseline version we don't need proper entity search. Putting in the ID of the Sense we want to reference is enough.
Task breakdown:
* [Task] Create properties for use in senses and forms. For example: "Rhymes with" could be a property referring to a Form, and "Translates to" a one referring to a Sense. Data type of these properties is "wikibase-item"! We might change this later.
* [Task] Output static HTML on forms/senses linking to other forms/senses. Literally static HTML with no formatter. Note that the actual data type of the properties in use is "wikibase-item", but the <a href="…"> links to forms/senses, e.g. `…/wiki/Lexeme:L5#L5-F11`.
* [Task] Introduce actual datatypes to link to forms and senses. (Check if T165341 is a duplicate or parent task.) New data types are "wikibase-lexeme-form" and "wikibase-lexeme-sense". (Must be with the "…-lexeme-…" prefix because there is no namespace to distinguish otherwise, decision made by @Jonas and @thiemowmde.) Data value type should reuse the existing "wikibase-entityid". Data type configuration should reuse everything from "wikibase-item".
* [Task] Introduce a dummy formatter for "wikibase-lexeme-form" and "…-sense" data types. Spits out HTML in the most simple way possible: `<a href="Lexeme:L5#L5-F11">Label (L5-F11)</a>`. Uses labels from items by turning `L5-F11` into `Q11`.
* [Task] Create a subclass of the item suggester for use on form/sense data types. Should be a straight subclass with no special code, except that it does return a value where the item ID is translated to a form/sense ID (`Q11` becomes `L5-F11`).
We assume this and {T165579} to be almost 100% exact copies including the subtasks listed there.