Persistence preset: global set of Tor bridges

Scope

In scope for D:Sponsor08:

• configuration of proxies, bridges , and pluggable transports
• allow users to change these persistent settings

In this issue, we will limit ourselves to save the last set of bridges that connected to Tor successfully. We'll work on per network settings in #18423.

Design

Designed in https://gitlab.tails.boum.org/tails/blueprints/-/wikis/network_connection#ux-design.

Details:

• We store the last set of bridges that connected to Tor successfully.
• If the user chooses autoconfig, we turn on "Configure a Tor bridge" automatically and feed them automatically into the bridges text area in the second screen.
• If the user chooses to hide Tor, we feed them automatically into the bridges text area in the second screen.

Tasks

• Replace f5f773ca mock code with UI interaction
• When we already have persistent bridges, change the label from Type in to Use