fix(MediaSettings): sync preferences with devices direct selection

[DorraJaouad]

☑️ Resolves

• Fix Device preferences are not saved when set from Talk settings #12185
• Fix "Apply settings" button of media settings is difficult to discover, especially on smaller resolutions #12120

🖌️ UI Checklist

🖼️ Screenshots / Screencasts

🏚️ Before	🏡 After

🚧 Tasks

• Do not show "Apply Settings" on changes that touch devices only.
• Update preferences needs to be called @update:deviceId event. This will cover both media settings and Talk settings devices changes.
• To move "check if preferences update is called at least once" to showModal(), because user may open and close media settings without any pref update and without reload. It makes more sense to also force it next time they open it.
• Split audio and video preferences update

🏁 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
• 📗 User documentation in https://github.com/nextcloud/documentation/tree/master/user_manual/talk has been updated or is not required

[Antreesy]

Changes look good to me. Let's wait for Daniel's input

[Antreesy]

Still not fond of the decision to open it only the first time, but with my comments that should match the issue description

[DorraJaouad]

Rebased

[DorraJaouad]

/backport to stable29