fix(helpers) move copyText function to web.js file

It gets bundled on mobile for no reason otherwise.

react/features/base/util/copyText.ts

@@ -0,0 +1,18 @@
+import clipboardCopy from 'clipboard-copy';
+
+/**
+ * Tries to copy a given text to the clipboard.
+ * Returns true if the action succeeds.
+ *
+ * @param {string} textToCopy - Text to be copied.
+ * @returns {Promise<boolean>}
+ */
+export async function copyText(textToCopy: string) {
+    try {
+        await clipboardCopy(textToCopy);
+
+        return true;
+    } catch (e) {
+        return false;
+    }
+}