jf_activity: paginated list in ui

added POST route for pagination to activity route, a count route, and
modified Search and PaginatedList a bit to support lists without search
fields (essentially just running an empty search). Visible by clicking
on a user's name in the accounts tab.

ts/modules/row.ts

@@ -0,0 +1,15 @@
+export abstract class TableRow {
+    protected _row: HTMLTableRowElement;
+
+    remove() {
+        this._row.remove();
+    }
+    asElement(): HTMLTableRowElement {
+        return this._row;
+    }
+
+    constructor() {
+        this._row = document.createElement("tr");
+        this._row.classList.add("border-b", "border-dashed", "dark:border-dotted", "dark:border-stone-700");
+    }
+}