Expose entireWord in updateFindControlState

Allow apps with supportsIntegratedFind to better monitor the find state.

A recognized use case is the Firefox findbar, its "not found" sound must
consider `entireWord` and only make noise when it is off.

See related implementation in
https://hg.mozilla.org/mozilla-central/rev/16b902cbcf26

This change can help if we have to move the implementation from cpp to jsm.

web/pdf_find_controller.js

@@ -1133,6 +1133,7 @@ class PDFFindController {
       source: this,
       state,
       previous,
+      entireWord: this.#state?.entireWord ?? null,
       matchesCount: this.#requestMatchesCount(),
       rawQuery: this.#state?.query ?? null,
     });