[wip] Remove multissid and enable multi instance

[hidrarga]

Problem

Closes #100

Solution

While I'm removing the multi SSID to make the app cleaner and simpler, I'm also enabling installation of multiple instances of the app. The user will be able to install one hotspot app per wifi device. The downside is that they won't be able to have multiple SSID on the same device (we could add this feature later, for instance by adding a "guest hotspot" option).

PR Status

• [ ] Code finished and ready to be reviewed/tested
• [ ] The fix/enhancement were manually tested (if applicable)

Automatic tests

Automatic tests can be triggered on https://ci-apps-dev.yunohost.org/ after creating the PR, by commenting "!testme", "!gogogadgetoci" or "By the power of systemd, I invoke The Great App CI to test this Pull Request!". (N.B. : for this to work you need to be a member of the Yunohost-Apps organization)

[hidrarga]

!testme

[yunohost-bot]

:carousel_horse:

[hidrarga]

I noticed that when usb devices are reloaded (see hot_reload_usb_wifi_cards function), all wireless device would go down. I don't have an easy solution for this right now, except manually restarting related hotspot :/

[hidrarga]

!testme

[yunohost-bot]

:v:

[hidrarga]

!gogogadgetoci

[yunohost-bot]

Alrighty!