refactor: configurable remote name for inserting snippets

This MR changes how we determine which remote to use. Originally when there were multiple remotes and the user didn't specify one in the settings, we just used one. Now we ask users which remote they want to use.

This is the first out of two MRs, this creates the plumbing for setting the preferred remote and adds it to one command, the second MR will use this plumbing for all commands.

On the video you see:

1. First you see an empty settings.json file
2. Then we invoke the insert snippet command
3. There are multiple remotes and we choose origin
4. The command works as expected and we insert a snippet
5. You see the preferred remote being added to the settings

Kooha-10-20-2021-15-40-03

Related to #459 (closed)