feat: block after vorta create and log status

[diivi]

Description

Fixes #1380
blocks vorta --create to log the result of the backing up operation.

Motivation and Context

Better UX for vorta --create

How Has This Been Tested?

Test GIF:

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have read the CONTRIBUTING guide.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

I provide my contribution under the terms of the license of this repository and I affirm the Developer Certificate of Origin.

[real-yfprojects]

There is a problem: A second main window opens while the backup is running.

[diivi]

There is a problem: A second main window opens while the backup is running.

What do you suggest I do for the second window? If I close it, will it run in the background until it exits?

[real-yfprojects]

What do you suggest I do for the second window?

Don't create a main window instance (nor a scheduler instance and so on).

[diivi]

Don't create a main window instance (nor a scheduler instance and so on).

I changed the code so it only adds the message_received event to the other instance and nothing else.

[real-yfprojects]

I notice that this can't handle when borg returns an error or when vorta --create is run twice simultaneously

[diivi]

I notice that this can't handle when borg returns an error or when vorta --create is run twice simultaneously

My last commit should handle borg errors right?

Also, how should I handle the second case? After handling Borg errors, I get this error when I run vorta --create twice simultaneously:
QAbstractSocket::waitForBytesWritten() is not allowed in UnconnectedState

[real-yfprojects]

After handling Borg errors, I get this error when I run vorta --create twice simultaneously:
QAbstractSocket::waitForBytesWritten() is not allowed in UnconnectedState

I see this being outputted too, but it doesn't stop code execution. I think the current networking code can only handle one client at a time resulting in this message when the first (or maybe the second) client has disconnected.

[m3nu]

if True is generally quicker to read than if not XX. And since we have a large code block under this condition now, it should get at least a comment on when this path is chosen. Still, keeping most of the code on the default path and dealing with exceptions some other way is preferable.