reader: Rename struct SyncgroupPrefix to a more generic 'TableRow'

MultiPart: 6/8

Change-Id: Iac272d680cb5f119eeb88e7ea17ee39f8b8731ae
diff --git a/web/browser/vanadium/syncbase/index.js b/web/browser/vanadium/syncbase/index.js
index 4557ca2..7f0f2a7 100644
--- a/web/browser/vanadium/syncbase/index.js
+++ b/web/browser/vanadium/syncbase/index.js
@@ -455,9 +455,9 @@
       // matches row keys. Rows have Vanadium object names of the form
       // <syncbaseName>/reader/db/<table>/<rowKey>, so a syncgroup prefix can be
       // thought of as a vanadium namespace glob over rows.
-      prefixes: [new syncbase.nosql.SyncgroupPrefix({
+      prefixes: [new syncbase.nosql.TableRow({
         tableName: 'files',
-        rowPrefix: 'c'
+        row: 'c'
       })],
       // mountTables: [ ... ] - actually a rendezvous point that is
       // permissable to mount to by the syncbase instance hosting the sync