View past log messages from the snackbar

[cmihai]

Is your feature request related to a problem? Please describe
Currently, all the pop-up notifications in the wallet disappear after a few seconds, or after the user dismissed them. However, the users might want to go back and review them after the fact -- for example, to remind themselves of the location where they backed up the wallet, or to see the last application error message in more detail.

Describe the solution you'd like

One of the two solutions would do:

• Either the application gets a new page, similar to the Console pop-up, which contains the past notifications,
• Or the notifications get written to a file somewhere, which the user can open in a text editor.

I'm more inclined to go with the second solution, because the log messages are persistent between restarts, and also it's less code to write.

[cornelius]

The second solution would basically result in writing a log file. This seems to be a good idea in any case. And there still could be added a way in the UI to show this log file if desired.