UI feedback for mic/camera mute

### Steps to reproduce

We should check that we don't wait for mute signalling to propagate before updating the status of the mute buttons. From looking at rageshakes, it looks like some users might end up thinking nothing has happened and clicking the button again. Ideal flow is probably: set streams disabled, update UI, send mute signalling events.

### Outcome

#### What did you expect?

#### What happened instead?

### Operating system

_No response_

### Browser information

_No response_

### URL for webapp

_No response_

### Will you send logs?

Yes

No file or test is named. Start by tracing the mic/camera mute button handler and its mute signalling path; verify that streams are disabled and the UI updates before signalling is sent. Done means the buttons respond immediately without waiting for signalling propagation.

Written by the indexing model from the issue text.