fix(federation): disable call buton if talk proxy hash is dirty

[Antreesy]

☑️ Resolves

• Fix Call button should be disabled when federated capabilities were updated #12864
• Not sure if we should allow chat with dirty hash (as we did before), but feels like we need to

🖌️ UI Checklist

🖼️ Screenshots / Screencasts

Moved toast to the top to see call button on th screenshot

🏁 Checklist

• 🌏 Tested with Chrome, Firefox and Safari or should not be risky to browser differences
• 🖥️ Tested with Desktop client or should not be risky for it
• 🖌️ Design was reviewed, approved or inspired by the design team
• ⛑️ Tests are included or not possible - in follow-up
• 📗 User documentation in https://github.com/nextcloud/documentation/tree/master/user_manual/talk has been updated or is not required

[nickvergessen]

Not sure if we should allow chat with dirty hash (as we did before), but feels like we need to

We should allow it, so people can recover their input etc. Also most of the settings don't touch chatting at all.

[danxuliu]

Tested and works 👍

Unrelated to this pull request, joining a federated conversation for the first time after logging in shows the Nextcloud Talk Federation was updated, please reload the page message. From the code it makes sense, as the capabilities would not be found in the browser storage so the hash can not match, but from a user point of view looks like a bug. I think that I read somewhere that this was a known issue, but I mention it just in case.