Tony/177 login button

[tonypioneer]

Pull Request Details

What issue does this PR address

• Replaced the logout button on the appbar with a dynamic authentication (login/logout) button.
• Fixed the issue that the page will be navigated to a default login page after the user is logged out
• Fixed the issue that users can only be navigated to a placeholder page saying that the logging is successful instead of the normal home page.
• Fixed the lint issues (locmax).

Associated Issue

• This PR relates to issue SOLIDUI: The logout button on the appbar should be replaced with login button if the user is not logged in #177

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Build and run the app.

Checklist

Complete the check-list below to ensure your branch is ready for PR.

• Screenshots included in linked issue SOLIDUI: The logout button on the appbar should be replaced with login button if the user is not logged in #177
• Changes adhere to the style and coding guidelines
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• Any dependent changes have been merged and published in downstream modules
• The update contains no confidential information
• The update has no duplicated content
• No lint check errors are related to these changes (make prep or flutter analyze lib)
• Integration test dart test output or screenshot included in issue #
• I tested the PR on these devices:
  • Android
  • iOS
  • Linux
  • MacOS
  • Windows
  • Web
• I have identified reviewers
• The PR has been approved by reviewers

Finalising

Once PR discussion is complete and reviewers have approved:

• Merge dev into the this branch
• Resolve any conflicts
• Add a one line summary into the CHANGELOG.md
• Push to the git repository and review
• Merge the PR into dev

[gjwgit]

Thanks @tonypioneer