'`toolbox enter`' | message "Error: container <container_name> not found"

- _toolbox v. 0.3_
- _host_: Fedora 44

**Description**

Hello. The non-existence of a container corresponding to the host's Linux distribution and version is a valid state. Therefore, reporting this state as an error is inappropriate.

**Steps to reproduce the behaviour**

1. Run '`toolbox create -y --release 45`'.
2. Ensure that the container _fedora-toolbox-44_ does not exist.
```
$ toolbox list -c
[...] CONTAINER NAME [...] STATUS [...]
[...] fedora-toolbox-45 [...] created [...]
```
3. See the error message.
```
$ toolbox enter
Error: container fedora-toolbox-44 not found
Entering container fedora-toolbox-45 instead.
Use the 'create' command to create a different Toolbx.
Run 'toolbox --help' for usage
```

**Expected behaviour**

A message in output such as "Container fedora-toolbox-44 not found/does not exist." would be appropriate.

Reproduce the behavior with `toolbox create -y --release 45`, then run `toolbox enter` while only `fedora-toolbox-45` exists. Trace the `toolbox enter` fallback output and update the message so this valid fallback is not reported as an error; verify the output matches the expected wording.

Written by the indexing model from the issue text.