fix numpy function hover missing name #1418

[asukaminato0721]

fix #1418

Added metadata-backed hover names by threading a display_name through every FindDefinitionItemWithDocstring so hover headers can still show identifiers even when we land in stub files or empty ranges.

Updated the hover formatter to try definition snippets, the metadata name, a type-derived fallback, and finally a lexical identifier; this restored headers for third-party symbols and ensured both WASM and native LSP paths behave identically

Introduced rich function rendering: callable tooltips now show (function) name plus a syntactically valid def name(...): ..., improving syntax highlighting in VS Code for cases like np.array.

[asukaminato0721]

improve #1416

[asukaminato0721]

fix #1348

[kinto0]

Thanks for looking into this! A few questions

it's unclear why these names are missing from your summary. are all of these bugs the same situation?

do we need all of these fallbacks? which ones are necessary in which situations?

I would like to see all this logic localized to one section. can this entire PR be a change to pyrefly/crates/pyrefly_types/src/display.rs?

[asukaminato0721]

Resolver didn’t keep a textual name when the definition expression was empty (e.g., stub attributes, keyword arguments, or type-only nodes). Fix: FindDefinitionItemWithDocstring now always carries a display_name, so when we do have definition metadata, we reuse that string.

Type-only lookup path – when we fail to find any definition (third-party binary stubs), we still need something readable. That’s why we fall back to metadata from Type::Function/Callable/BoundMethod/Forall.

Literal identifier under the cursor – in the degenerate case where neither of the above provides anything (e.g., a failing resolver on a local scratch buffer), we lex the identifier so we can at least echo the token.