Remove access without account

[MrFlashAccount]

Pull Request Description

Closes: https://github.com/enso-org/cloud-v2/issues/1229

This PR removes button "Continue without creating an account" on Login page. Aslo, This PR removes weird behaivor when dashboard goes into offline mode in canse if network error is happening

Important Notes

Checklist

Please ensure that the following checklist has been satisfied before submitting the PR:

• [ ] The documentation has been updated, if necessary.
• [ ] Screenshots/screencasts have been attached, if there are any visual changes. For interactive or animated visual changes, a screencast is preferred.
• [ ] All code follows the Scala, Java, TypeScript, and Rust style guides. In case you are using a language not listed above, follow the Rust style guide.
• [ ] Unit tests have been written where possible.