[AD-446] Add a way to disable confirmation in GUI

[maksbotan]

Description:
Problem: GUI uses tedious confirmation dialogs to make sure the user
understands what he is doing when removing wallet, sending transactions
or creating new wallet. However, this may be inconvenient for testing
and developing.

Solution: add runtime-configurable setting to disable confirmation
requests for those actions.

YT issue: https://issues.serokell.io/issue/AD-446

Checklist:

• Updated docs if necessary
  • README
  • TUI usage guide
  • GUI usage guide
  • Configuration documentation
  • GUI architecture documentation
• My code complies with the style guide
• Tested my changes if they modify code

[gromakovsky]

Unfortunately this issue wasn't specified properly. I've updated its description, now it has acceptance criteria.
I think that it should be part of dhall configuration, so that it can be set once and forever.
Ideally the settings dialog should update the value in configuration file, but we don't have a way to modify this configuration from the application itself yet. I think it's ok to have this setting in GUI, but write that it will apply only to the current session.
Also note that we need it in TUI as well. I think we don't need to be able to modify this value from TUI though.
Also I think that over GUI shouldn't diverge from zeplin, so if you change something (e. g. add something new), please notify @a-rukin about it so that he can update zeplin (and maybe suggest a better design).

[maksbotan]

I made additions to satisfy criteria in YT. This can be reviewed per-commit to simplify things, after approval I intend to squash the commits.

Probably this functionality should also be documented in GUI usage guide, however that guide does not mention settings at all at the moment, so this can be done in a separate task.