Option to hide groups without a name

[Nimmidev]

When using scli i have groups with weird names like "M4u70uK1FgpR83jSHWNBYcKne4DX/GtXjyIoFihxM5c=".

After investigating a bit it seems like scli is using the group id if the name is null.

Output of signal-cli listGroups:

If this is intended behavior it would be great if there was an option to hide groups with no name. Especially because these groups are the ones you are no longer part of i.e. you cant use them anyways.

(I am not sure if this is actually an issue with signal-cli. So if you think such entries shouldn't be in the listGroups output anyways please tell me and i am gonna open an issue there.)

[exquo]

More importantly than having Name: null, these groups are all Active: false. They are indeed groups that you are no longer a member of (see https://github.com/AsamK/signal-cli/discussions/975)

It would make sense to omit such groups from scli's contacts list if there is nothing else useful about them, such as the past conversation history. Generally, we should do the same here as the official clients.

[exquo]

In line with following the official clients' behavior, signal-cli does not delete the group after leaving it (https://github.com/AsamK/signal-cli/discussions/975#discussioncomment-3093406). However, after leaving the group, its name in listGroups does not seem to change.

To delete such group from signal-cli's list (and, correspondingly, scli's too), you can use your master device (signal on the phone), or signal-cli directly. That is, until the quit / delete group functionality is added to scli.

[exquo]

Correction: seems like deleting a group is not sync'd across devices. So we do need an option to delete groups from scli. To not reopen this issue, tracking it in the new one: #210.