Move logic from DmfsTaskList companion object to DmfsTaskListProvider

[sunkup]

Part of refactoring synctools tasks.

Required for bitfireAT/davx5-ose#1934 .

For reference only: Similar AndroidCalendar changes are made in #28

[rfc2822]

I think there are unoptimized imports. Looks good otherwise on the first glance!

[sunkup]

Ok. Ready for review. Please pay close attention to the uri helper methods. That is: "tasksUri", "taskListUri", etc. I found those a tad confusing ...

[rfc2822]

Exception handling: sometimes we have a try/catch Exception (with re-throw to LocalStorageException), sometimes try/catch RemoteException, and sometimes no try/catch.

I think synctools should make sure that every call throws a LocalStorageException in case of errors, but not a RemoteException. So I'd catch RemoteException on all provider operations and use it as the cause of the LocalStorageException.

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Generally, how do you want to handle tests? Always have almost-complete tests in every PR or do you want to migrate the architecture first and then, as soon as a class is "as it should be", make sure that all its tests are written?

[sunkup]

Generally, how do you want to handle tests? Always have almost-complete tests in every PR or do you want to migrate the architecture first and then, as soon as a class is "as it should be", make sure that all its tests are written?

I would usually want to go by the first approach, but in this case, since I feel there is a certain pressure to be done soon with the rewrite, I'd add the tests when all else is done.

[rfc2822]

Didn't check everything in detail but looks good!