fix(completions): sort JSDoc @param suggestions by declaration order

[creazyfrog]

Summary

Fixes #20183

Problem

When triggering completions after @param in a JSDoc comment, all parameter suggestions had the same sortText: "11" (SortText.LocationPriority). This caused them to be sorted alphabetically by name rather than by their declaration order in the function signature.

/**
 * @param |
 */
function foo(z, a) {}
// Completions before fix: ["a" (sort: "11"), "z" (sort: "11")]
// Completions after fix:  ["z" (sort: "110000"), "a" (sort: "110001")]

Fix

Expose the parameter index i from the mapDefined callback and build a per-parameter sortText that encodes declaration position:

-return mapDefined(func.parameters, param => {
+return mapDefined(func.parameters, (param, paramIndex) => {
     ...
+    const sortText = (SortText.LocationPriority + String(paramIndex).padStart(4, "0")) as SortText;
     return {
         ...
-        sortText: SortText.LocationPriority,
+        sortText,
     };
 });

This produces "110000", "110001", … — parameters stay within the same priority tier ("11" prefix) but are now ordered by their position in the function signature. The fix applies to both named parameters and destructuring parameters.