Bump matrix-sdk dependency to 0.10.0

[kenrachynski]

There is a warning that popped up during this change and I have no idea how to deal with it.

warning: elided lifetime has a name
   --> src/message/mod.rs:964:29
    |
957 |     pub fn show_with_preview<'a>(
    |                              -- lifetime `'a` declared here
...
964 |     ) -> (Text<'a>, Option<(&dyn Protocol, u16, u16)>) {
    |                             ^ this elided lifetime gets resolved as `'a`
    |
    = note: `#[warn(elided_named_lifetimes)]` on by default

Otherwise, this seems to be running fine

[kenrachynski]

Comment from @bnhbvr in #iamb-dev:

i think that history_visibility() became something returning an Option now, so using {:?} when rendering it in a formatted string will show None or Some(…), which is not super nice for the user. Might prefer something like room.history_visibility().map(ToString::to_string).unwrap_or_else(|| "<unknown>".to_owned())⁦
hmm that might fit in a single map_or_else call, actually  

[bnjbvr]

Reiterating my comment in the right place :)

This is where we're calling Room::history_visibility(), which will now return an Optional value, None meaning the value is unknown because the related state event hasn't been sync'd yet.

I think it might be nicer in terms of UX to display it as "unknown" when it's set to None, instead of rendering None (and then we can also keep the current formatting when it's known, instead of Some(Public) or somesuch).

[kenrachynski]

Honestly, I'm not sure I even like the Some("shared") when I do :room history show. Good to know where it displays, at least.