Fix Tab-to-accept crashing for user-defined function completions

[NisargJasani0602]

Fixes #4272

Issue:

buildVarOrFunctionOption() in contextAwareHinter.js expects state and pos as separate positional arguments (matching its sibling builders, buildMethodOption and buildGlobalHintOption), but its call site was bundling
them as properties inside the options object instead. Since the function's destructuring pattern doesn't include state/pos, both silently ended up undefined inside the function.

That undefined state got captured in the completion's apply closure. When accepting a user-defined function completion via Tab, state.doc.lineAt(pos) threw TypeError: Cannot read properties of undefined (reading 'doc'). The Tab
keymap handler treats a failed accept as "unhandled" and falls through to the next binding, so nothing got inserted — matching the reported bug.

This only affected completions for user-defined functions/variables from the app's custom hinter; built-in p5 keywords and CodeMirror's own local-scope suggestions were unaffected (which is why the popup could show two entries for
the same identifier — one broken, one fine).

Changes:

• Fixed the buildVarOrFunctionOption() call site in client/utils/contextAwareHinter.js to pass state and pos as separate trailing arguments instead of bundling them inside the options object.

I have verified that this pull request:

• has no linting errors (npm run lint)
• has no test errors (npm run test)
• has no typecheck errors (npm run typecheck)
• is from a uniquely-named feature branch and is up to date with the develop branch.
• is descriptively named and links to an issue number, i.e. Fixes #123
• meets the standards outlined in the accessibility guidelines