[dashboard] Refactor Login layout and messaging for Gitpod Classic users

[Siddhant-K-code]

Description

Update the login interface to accommodate better Gitpod Classic users, including layout adjustments and new messaging about the transition to Gitpod Flex.

For more context for review, check this internal conversation

Related Issue(s)

fixes NEXT-2072

How to test

Documentation

Preview status

Gitpod was successfully deployed to your preview environment.

• 🏷️ Name - login-page6e9e7b3a2c
• 🔗 URL - login-page6e9e7b3a2c.preview.gitpod-dev.com/workspaces.
• 📚 Documentation - See our internal documentation for information on how to interact with your preview environment.
• 📦 Version - login-page-non-enterprise-users-gha.30288
• 🗒️ Logs - GCP Logs Explorer

Build Options

Build

• /werft with-werft
  Run the build with werft instead of GHA
• leeway-no-cache
• /werft no-test
  Run Leeway with --dont-test

Publish

• /werft publish-to-npm
• /werft publish-to-jb-marketplace

Installer

• analytics=segment
• with-dedicated-emulation
• workspace-feature-flags
  Add desired feature flags to the end of the line above, space separated

Preview Environment / Integration Tests

• /werft with-local-preview
  If enabled this will build install/preview
• /werft with-preview
• /werft with-large-vm
• /werft with-gce-vm
  If enabled this will create the environment on GCE infra
• /werft preemptible
  Saves cost. Untick this only if you're really sure you need a non-preemtible machine.
• with-integration-tests=all
  Valid options are all, workspace, webapp, ide, jetbrains, vscode, ssh. If enabled, with-preview and with-large-vm will be enabled.
• with-monitoring

/hold