related db calls should be put into a storage method that has a tx

[tomholub]

This should be made a transaction in storage (can be another PR later) else it produces inconsistent results.

Originally posted by @tomholub in #1165 (comment)

[tomholub]

[tomholub]

applies to any place that we are doing more than one db write call within some method. Whether that is done in a loop or updating two tables etc.

That way we will not end up with unpredictable database states if one operation succeeds but next one fails.

[tomholub]

@sosnovsky maybe you'd be able to give an example

[sosnovsky]

@ioanmo226 we can use removePubKey method from task description as example (https://github.com/FlowCrypt/flowcrypt-ios/blob/master/FlowCrypt/Functionality/Services/Local%20Contacts%20Service/LocalContactsProvider.swift#L121)

// current version
for key in keys {
    try storage.write {
        storage.delete(key)
    }
}

// transaction version
try storage.write {
    for key in keys {
        storage.delete(key)
    }
}

Then all key deletion operations will be executed as 1 transaction, and if any operation fails - full transaction will be cancelled.

[tomholub]

And similarly for any other operations that happen either in a loop, or where >1 database operations happen inside one method.