[Suggestion] Add options to skip "Installing basic packages" step for distrobox-enter

**Is your feature request related to a problem? Please describe.**
Every time you enter a stopped container, `distrobox enter` will also install basic packages (this behaviour is probably inherited from `distrobox init`). But if you don't have internet yet, this step is either stuck or errors out (at least for fedora containers, I am not sure if this happens to other distributions). Sometimes we need to use the tools inside the distrobox without the internet.

**Describe the solution you'd like**
Maybe adding options to skip installing basic packages for `distrobox enter` can solve this problem.

**Describe alternatives you've considered**
Or skip installing basic packages automatically when there is no internet connection.

**Additional context**
This is what happens if I shutdown my internet and try to enter a fedora container: