[Refactor] Unified Home Routing with App Layout & User Context

[blu3eee]

**Note: This should be the last frontend refactoring for the issue #346

Currently, we have separated Header (logged in/out header, logged in/out footer, and 2 routes logged_in_home and logged_out_home). I want to introduce user context that will change when user is logged in and the components will display accordingly.

PR changes:

• Changing/refactoring the header, footer, and home components into one Header component, footer component with user context and Layout.
• Minor styling changes in Two-factor banner component
• Styling changes with brand logos (google, discord) for 3rd party login buttons

This PR should resolves:

• Theme button #119
• refactoring issue #346 In addition, by refactoring the files and components, issue #324 by removing example profile out of the page layout and the sidebar bug in #325 is also fixed.

Please review it and let me know if these changes are reasonable. Thank you!

Demo for the changes:

https://github.com/LetsMesh/Site/assets/88558991/50c8fff0-06d3-489d-a3ce-3bbb3f315164

[Darren52BT]

I think most of the changes are good though I'm a bit confused on what you intend GridContainer to do since I see you overriding the justify-content and align-items props that you set for it here.

Upon testing though everything looks good.

[blu3eee]

skimmed thru the issues and realized this PR also resolved some of the bugs: #324 and #325