[Story] EX LLS: reply and thread

### Description

* As a user
* I want to be blocked to perform certain actions that does not work or does not make the UX good
* So that the actions that I do work and the UI/UX stays consitent

# Acceptance criteria
- When a LLS is started, user cannot reply to the state Event `org.matrix.msc3672.beacon_info`. This is not supported by the Rust SDK, and so it does not work. When the reply is done by Element Web, it works, and the rendering is OK on EXA. But better to disable the ability to reply to such Events globally.
- User cannot create a thread from a LLS start/stop Event
- User cannot create a LLS from a thread timeline. Currently the LLS is started but there is no immediate UI feedback as the banner is only rendered on the Main timeline on mobile. It's probably better to disable the ability to start a LLS from a thread.

# Dependencies
- None

# Out of scope
- Nothing

# Questions
- [x] None

# Subtasks

I'll create subtasks on the 3 plateformes if we agree on the description above

### Android
-

### iOS
-

### Rust
-

### Other
-

Start by reviewing the acceptance criteria and determining how the work should be split across the Android, iOS, and Rust subtasks. Inspect the client handling for LLS start/stop events, thread timelines, and replies to the beacon_info state event; done means all three unsupported actions are disabled and supported LLS behavior remains available.

Written by the indexing model from the issue text.