Searching encrypted rooms does not warn you if indexing is incomplete

### Steps to reproduce

1. Log into a new desktop session
2. Go to a DM
3. Search for something you can see in the scrollback
-> see result shown correctly
4. Search for something you know is in the room history but haven't scrolled to yet
-> Be told that there are no search results (have been trying to search this conversation for some time at this point)

### Outcome

#### What did you expect?
If the conversation is still being indexed, a warning about that. That the conversation I am looking at is prioritised for indexing over ones which I haven't openned.
Maybe that clicking the request keys link causes the decrypted messages to be indexed first?

#### What happened instead?
I can't search an encrypted conversation because the search tells me that there are no matches (and this is blocking my work).

Light theme is web client, dark theme is desktop client:


### Operating system

Arch Linux

### Application version

element-desktop-1.9.2-2, electron-15.2.0-1

### How did you install the app?

Distro package

### Homeserver

_No response_

### Will you send logs?

No