fix(ui5-tooling-modules): patch WebComponentRegistry to fix ShellBarSearch gen/ wrapping

@ui5/webcomponents-fiori@2.21.x exports a DIFFERENT internal class named
ShellBarSearch from dist/shellbar/ShellBarSearch.js (a search controller).
WebComponentRegistry processes this export AFTER the public dist/ShellBarSearch.js
export, overwriting the class's module path from "dist/ShellBarSearch.js" to
"dist/shellbar/ShellBarSearch.js". This makes the registry lookup fail in
lookupWebComponentsClass, so ShellBarSearch never receives a gen/ UI5 wrapper.

Fix: change = to ??= in WebComponentRegistry.js#parseExports so the module
path is only set on the first export (the correct public one), not overwritten.

Also adds patch-package and postinstall hook to apply the fix persistently.

Author: kgogov