cmsBaseUrl is unavailable or malformed

I'm attempting to install while using Drupal 7 on Lando. This might also be relevant for attempting to install in other containers. I get an error and it fails:

```
$ lando ssh
www-data@045f79017765:/app$ ./cv core:install
Found code for civicrm-core in /app/sites/all/modules/civicrm
Found code for civicrm-setup in /app/sites/all/modules/civicrm/vendor/civicrm/civicrm-setup
WARNING: (system) CiviCRM memory check: You have -1 allocated (minimum 32Mb, recommended 64Mb)
ERROR: (system) cmsBaseUrl: The "cmsBaseUrl" (http://localhost/././) is unavailable or malformed. Consider setting it explicitly.
```

I'm guessing it doesn't like the environment variable that Lando is setting. I may attempt to manually set it (though it would be better if we didn't have to). It doesn't say *where* to set it. Perhaps it requires setting `$base_url` in settings.php? (Though Lando actually provides 2 options for URLs for the sites).

By the way, I'm sshing to the Lando container so that I can run `cv` and have it recognize the database.

Start with the `cv core:install` entry point and the handling of `cmsBaseUrl`, using the reported Lando/Drupal 7 command as the reproducer. Check how Drupal's `settings.php` and `$base_url` relate to the generated `http://localhost/././` value. Done means installation no longer rejects a valid container URL, or clearly reports where `cmsBaseUrl` must be set.

Written by the indexing model from the issue text.