Expand isReasonableGitURL

What does this MR do and why?

Ahead of deleting the FF import_by_url_new_page , I notice while updating spec/features/projects/new_project_spec.rb which tests the old URL Import form, that immediate feedback is expected when a user enters a localhost url:

https://gitlab.com/gitlab-org/gitlab/-/blob/master/spec/features/projects/new_project_spec.rb#L450

While the backend would correctly handle this case, it seems find to extend isReasonableGitURL to also check for some localhost in the new Vue forms : import_by_url_form.vue and import_by_url_to_existing_project_form.vue.

As a result, "Enter a valid URL" will display on blur after entering some local host urls. Note: This isn't a comprehensive check.

References

Clean up use of old URL import code

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Ensure feature flag import_by_url_new_page is enabled
2. In admin settings make sure Repository By URL is enabled in admin/application_settings/general#js-import-export-settings
3. Navigate to a group -> Create Project -> Import Project -> Repository by URL
4. Enter a url like http://127.0.0.0 and click tab. You should see the error prompt beneath the input.

MR acceptance checklist

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Related to #588515 (closed)