Draft: Implementation of alarm management

Things related to alarms performed in this MR:

1. Implement the base AlarmWidget class, which is used to provide user-friendly messages/actions for each alarm.
2. Implement a modal screen that displays information about the alarm and how to get rid of it.
3. Store alarms for each account in node data using a dedicated Alarm data class.
4. Implement custom models for each of the following alarms:

• governance voting expiration
• recovery account warning listed
• declining voting rights in progress
• changing recovery account in progress
• governance votes never created

Except for things related to alarms:

1. Fixed a situation where leaving the screen (noted in Governance) causes TUI to hang. Related: https://github.com/Textualize/textual/discussions/3171
2. Add a details button for each account in the dashboard (alarms are part of the details).