Minor UI improvements

Summary:
Addresses feedback from: https://github.com/facebook/flipper/issues/2076

- fix filtering non-string columns
- fix overflow in filter dropdown
- hide app column on all devices
- show pid column on android, to simplify filtering per app

Reviewed By: passy

Differential Revision: D27188458

fbshipit-source-id: b6180fb5a8d0a47e50dd5dc3533da3ff1b0a1a2e

desktop/flipper-plugin/src/ui/datatable/DataTableManager.tsx

@@ -323,13 +323,13 @@ function addColumnFilter<T>(
   disableOthers: boolean = false,
 ): void {
   const column = columns.find((c) => c.key === columnId)!;
-  const filterValue = value.toLowerCase();
+  const filterValue = String(value).toLowerCase();
   const existing = column.filters!.find((c) => c.value === filterValue);
   if (existing) {
     existing.enabled = true;
   } else {
     column.filters!.push({
-      label: value,
+      label: String(value),
       value: filterValue,
       enabled: true,
     });