Transfer: add support for outputs import / export

[selsta]

Requires monero-project/monero#7678

Resolves #2816

[selsta]

@rating89us please review / approve

[rating89us]

I'm getting this error:
W qrc:/pages/Transfer.qml:1107: TypeError: Type error

[selsta]

@rating89us how did you get this message?

[rating89us]

On view-only wallet, I clicked the export button. A file browser window opened and I entered a filename, when I clicked on the save button, no file was created and this error message appeared on the console.
I'm using Ubuntu.

[rating89us]

I didn't import monero-project/monero#7678 before testing this PR. Is it included in master?

[selsta]

I didn't import monero-project/monero#7678 before testing this PR. Is it included in master?

It's included in v0.17.2.3 and master. Will test in view only wallet.

[selsta]

@rating89us Thanks, found an issue. Updated and was able to export fine now.

[rating89us]

1. Output exporting is working now on view-only wallet. I suggest we add a feedback for the user:
   appWindow.showStatusMessage(qsTr("Outputs successfully exported to file") + translationManager.emptyString, 3);

2. When importing the outputs file in cold wallet, I get this error:
   W qrc:/pages/Transfer.qml:1121: TypeError: Property 'importOutputsDialog' of object Wallet(0x7f342a9d7b20) is not a function

[selsta]

Output exporting is working now on view-only wallet. I suggest we add a feedback for the user:

Fixed

When importing the outputs file in cold wallet, I get this error:

Fixed.. had copy paste mistake

[selsta]

Updated one more time to print success / error message.

[rating89us]

Now it's working for me.

I think we should also print success / error messages for importing/exporting key images.

[selsta]

Also updated error string here.