Additional "context" setting to switch between "personas"

Probably all Akiflow users have at least 2 personas or roles when they are using the tool: "private" and "work". When working as a freelancer or with multiple jobs, this can even get more complicated.

There was already a suggestion to include "areas", but I would suggest to extend this a little bit:

• There is a default scope, so no change of behaviour

• A scope defines the default calendar for task assignments

• A scope sets a default project (even "none") to apply to new manual & synced tasks

• A scope defines a default filter setting to projects (none, one or more) to apply to all views

• All integrations should allow to define a default project

• Maybe integrations should be defined on a per-scope level?

• Scopes might have a dedicated color scheme to make them more recognizable

• Scopes might be scheduled (e.g. switch to "private" on weekends or to "vacation" while on vacation, which hides most of the tasks)

This shouldn't break anything, and would even allow to define scopes to have a common view on personal and corporate tasks (e.g. contexts "private + work", "work", "private", "family", …).