jsonrpc: add functions missing for desktop migration

[Simon-Laux]

It's the last function that still uses the deltachat-node bindings in desktop. the purpose of the function is to make sure that a user can update from the old/early versions of delta chat and still keep their account.

https://github.com/deltachat/deltachat-desktop/blob/69f3a76e853f20c4d1007dd0edb0c260dd6f4831/src/main/deltachat/controller.ts#L150

The task is to move this function to a jsonrpc method and create tests for it to ensure it can successfully migrate the data from the old versions to the new version.

For this I collected test data from all released versions: https://github.com/deltachat/dektop_migration_test_data
This test data should be deduplicated (actually there are only 3-4 different formats, we don't need to move all test data to the core repo, only the parts that matter).
I logged in into the same 2 accounts in these test data, so in the test try migrating the data from those folders and then check if both accounts still exist and are configured.

[hpk42]

does the whole migrateToAccountsApiIfNeeded() function need to be ported to Rust? Seems potentially involved specially for someone not well versed in rust.

[nicodh]

I would suggest we show a message if old account format is detected:

Your account data is not compatible with current version of Delta Chat.
Please install Version 1.44 (Link) first to migrate your accounts to the new format.
After that you install and run the newest version.

[Simon-Laux]

I thought about this again, and came to the conclusion that it's better to keep in desktop, then for the tauri version we can either just ignore the legacy versions or need to reimplement the logic in rust.
I'll rename this issue to be for the missing jsonrpc apis