Add Trash to sidebar & dispaly trashed documents

Adds a Trash option to the sidebar. This new entry allows users to view trashed documents, fetched using DocumentsContract.buildTrashDocumentsUri

Bug: 409265240
Test: atest DocumentsUIGoogleTests:com.android.documentsui.TrashFileLoaderTest
Test: atest DocumentsUIGoogleTests:MenuManagerTest
Flag: com.android.documentsui.flags.enable_trash_flow_ro
Change-Id: If0ae385f524643f2a86c2aaecd4f9e2cd2cb63e8