Correct text of "INSTALLED" label in Library/Boards Manager

An "INSTALLED" label is shown on the items in the Library Manager and Boards Manager views that are currently installed
on the user's system.

During some work to add missing internationalization to the UI strings, this text was changed to "INSTALL". That text is
not appropriate for what this label is intended to communicate.

The regression is hereby corrected, while retaining the internationalization of the string.

Author: per1234

arduino-ide-extension/src/browser/widgets/component-list/list-item-renderer.tsx

@@ -59,7 +59,7 @@ export class ListItemRenderer<T extends ArduinoComponent> {
           className="installed"
           onClick={onClickUninstall}
           {...{
-            install: nls.localize('arduino/component/install', 'INSTALL'),
+            install: nls.localize('arduino/component/installed', 'INSTALLED'),
             uninstall: nls.localize('arduino/component/uninstall', 'Uninstall'),
           }}
         />

i18n/en.json

@@ -145,6 +145,7 @@
       "by": "by",
       "filterSearch": "Filter your search...",
       "install": "INSTALL",
+      "installed": "INSTALLED",
       "moreInfo": "More info",
       "uninstall": "Uninstall",
       "uninstallMsg": "Do you want to uninstall {0}?",