@uppy/provider-views: add e2e tests for Server side search (#6015)

Tests added as discussed in
[slack_discussion](https://transloadit.slack.com/archives/C0FMW9PSB/p1759931999124149?thread_ts=1759700542.941939&cid=C0FMW9PSB)

directory structure mocked : 

```
root/ 
├── first/
│   ├── second/
│   │   ├── third/
│   │   │   ├── nested-target.pdf
│   │   │   └── new-file.pdf
│   │   ├── deep-file.txt
│   │   ├── target.pdf
│   │   └── workspace.pdf
│   └── intermediate.doc
├── workspace/
│   └── project/
│       └── code.js
└── readme.md

```

Some of the mocked responses in CompanionHandler.ts aren’t used in the
tests, but I’ve kept them to preserve the legitimacy of the above
directory structure.

Author: qxprakash

packages/@uppy/dashboard/package.json

@@ -56,6 +56,7 @@
   },
   "devDependencies": {
     "@uppy/core": "workspace:^",
+    "@uppy/dropbox": "workspace:^",
     "@uppy/google-drive": "workspace:^",
     "@uppy/url": "workspace:^",
     "@uppy/webcam": "workspace:^",